Reverse Osmosis and growing cannabis (Part 1)

[seymore_budz]

Reverse Osmosis and growing cannabis (Part 1)

Hey all, I thought I’d write this post to revert back to if I need to and share some of the knowledge I’ve picked up along the way by error on my part and research online. First though; a little disclaimer, I’m not a plant scientist or any type of other scientist and have zero qualifications in this field. I’m just standing on the shoulders of giants and collating this info as well as relying some personal experiences to provide you my opinions on using reverse osmosis water when growing cannabis. This is not an academic paper and I gloss over a lot of the details. I highly encourage you to do your own research if this post interests you. That being said, I hand on my heart believe everything I’ve said here is factual. Also, could I also say, if you notice a mistake or you can elaborate on something covered her or if you just want to give your opinions, please post here :D I love to hear others thoughts and opinions and knowledge shared is what keeps the industry kind of honest.

I think we should kick this of with a question; what is water? I know that sounds stupid, but we need ask ourselves this question when trying to decide what water to use for our precious plants. You may be saying to yourself, well it’s H2O right? Water is so much more than just a compound. Water is considered the universal solvent. In it’s purest form, water is very reactive and will strip minerals away from anything it comes into contact with. It’s these properties that makes it essential for life. So, to answer the question when considering the context, I regard water as a solvent. Sorry about the simplified high school biology lecture but I wanted to set the scene for the rest of the post.

Next, let’s talk about water quality. What makes water good water for growing cannabis? Water quality can be measured by multiple factors but let’s concentrate on growing. To answer the above question, we need to look at what cannabis requires to thrive and what factors could influence the quality of the plants. Once we consider this, we can create a set of criteria that we can use to determine what’s required to make water good quality. Here’s my list of variables that could influence the grow in some way.

1) Concentrations of dissolved oxygen (DO).

Although water is made up of hydrogen and oxygen, some oxygen atoms hang about in-between the water molecules. This is what we call dissolved oxygen. These oxygen atoms are what keep the water healthy. Plants will get most of their oxygen from photosynthesis but dissolved oxygen is important for aerobic respiration as well as keeping the aerobic bacteria healthy. In hydroponics, the DO will help keep the roots strong and healthy. If a plant doesn’t have enough DO in hydroponics, the roots will become damaged, osmosis is effected and the plant cannot take up enough water. It also causes the aerobic bacteria to die and anerobic bacteria can thrive and cause root rot. In soil, the microlife that feeds the plants also make use of the DO.

2) Harmful phytotoxic substances or organisms.

Herbicides and bacterial phytotoxins can be devastating to a crop as well as end up in the plants tissues for you to ingest .These types of contaminants can be subtle and go unnoticed. They can also baffle the best of growers as they normally present themselves as deficiencies in plants and that leads people down the wrong road.

3) Salinity.

This is what most of us think of when we’re considering the water quality in regards to hydroponics. This is due to the first two being only a real concern when the water is sourced from somewhere other than the municipal supply. Us hobby growers would normally turn to the municipal supply coming in to the property and as long as you live in a country where the tap water is safe to drink, you will very rarely find low levels of DO or harmful pathogens as the water has been pretreated before it reaches your house. Salinity is the amount of dissolved salts that are in the water. This is normally measured as water hardness.

As previously discussed, water in it’s purest form is very reactive and will dissolve most things it comes into contact with. We have hard water here in the UK but what is water hardness? Quite simply, water hardness is a representation of the amount of dissolved salts in the water. This is normally made up of calcium carbonate, magnesium sulphate. It can also be made up of lots of different things but because most city water is sourced from groundwater, these two compounds are the usual suspects. Nutrient suppliers base their formulas based on the amount of calcium carbonate and magnesium sulphate in the water as well as most people use either the total amount of calcium or an aggregate of the two figures to determine the threshold where water is considered hard or soft. You can probably check out the hardness and the content of your municipal water by heading over to your suppliers website. Most water suppliers publish their analysis results.

Generally guidelines are as follows, 0 to 60 mg/L (milligrams per ltr) as calcium carbonate is classified as soft; 61 to 120 mg/L as moderately hard; 121 to 180 mg/L as hard; and more than 180 mg/L as very hard. From what I’ve read and seen, cannabis is a very active and hungry plant and needs at least 200ppm of Ca and 60ppm Mg for healthy growth in optimal conditions so even very hard water still doesn’t contain the amount of calcium that’s required to sustain healthy growth. I’ve glossed over a lot of the details in a lot of the subjects discussed above to keep the word count down and make this write up easier to digest so don’t hate on me for that :D

So, considering all above, it’s not looking good for the RO water so far? If all that I’ve said above is correct, why would anyone consider purifying their municipal supply? Most nutrients have been formulated to fit the profile of the water and the amount of individual and even hard water isn’t that bad for cannabis. Well calcium carbonate and magnesium sulphate isn’t the full picture and there is something else lurking in the water that seems to be more of a concern to the organic growers and that’s chlorine.

Chlorine or chloramine is normally added to the municipal water as a disinfectant because it’s cheap, effective and not thought to be harmful to humans in the amounts applied. Water suppliers moved from chlorine to chloramine because it’s more stable and hangs around in the water for longer. They may swap from chlorine to chloramine from time to time as chlorine is more aggressive so may be used as a flushing agent.

Bacteria grows everywhere on this planet. It’s thought to be the oldest living thing on the planet and will probably be around long after humans go extinct (probably not that far off considering the current year so far). I see bacteria is being the glue that bridges the gap between atomic elements and living organisms. We rely on them to survive as does most living things. For that reason, I’m a firm believer that we need it in both hydroponics and soil for a plant to reach it’s full potential and that’s why I don’t like to run products like hydrogen peroxide in my grows.

Due to the sterilization properties of chlorine, it was widely thought that it would kill the microlife in the soil if plants are watered with chlorinated water. This myth has been busted multiple times and chlorinated water will not harm the microlife in your soil. Chlorine is short lived and will off-gas pretty quickly but what about the chloramine? Without going into too much detail, the chlorine ammonia bond is no match for mother nature and is quickly torn apart by the organic matter in the soil and then the chlorine and ammonia off-gas out of the soil or is consumed by the plant. But why do we have these products like EcoSys neutralise that claim to be essential for cultivating healthy microlife? Well at first, I thought it was all snake oil but after a few conversations with others, I’ve changed my opinion. The chloramine isn’t harmful to the soil but could be harmful if you’re adding the bacteria to municipal water directly. So adding beanie products to water that hasn’t been neutralised could indeed kill off the beneficial beanies you’ve paid for. There may be more ways to neutralise chloramine, but only know of the following.

1) Humic acid

Humic acid does the same thing and breaks the bond between chloramine and ammonia.

2) Ascorbic acid (Vitamin C)

Ascorbic acid will react with the chloramine and chlorine and neutralise it pretty fast. This is the active ingredient in most products used in horticulture and aquariums etc.

We’ve gone off on a tangent for a little bit here but it’s all relevant to the title in this post. Now you’ve read all the above, are you still considering reverse osmosis water? Maybe you have other issues, take your water from another source than the supply to your property or your water is like mine and is so hard you need to buy a new kettle every few months, you may want to consider reverse osmosis. The reason why I started part one like this is because 99% of you out there shouldn’t even be considering reverse osmosis. Bottom line is reverse osmosis comes with it's own set of issues and your tap water will grow great cannabis. For the rest of you, reverse osmosis brings a whole host of benefits like being in total control of your water, less bicarb build up, less chances of bacterial or viral infections and also some downsides. In part two of this write-up, I’ll go deeper into the details of the benefits and caveats of using reverse osmosis water for growing cannabis.

[TTL]

Thanks for sharing!

[Josh]

Love the write-up man well done

The only thing I have a different opinion on is when you said -
"Most nutrients have been formulated to fit the profile of the water"

I think most companies formulate their recipes for RO water, easier for the results to be consistent with growers. Because as you stated, tap is different everywhere you go

Unless that's what you meant, then ignore me really high atm

Sent from my LGMP260 using Tapatalk

[trid]

I’m very new, but I’m looking for a “ constant” in my water. So when I mix my nutes I know what to expect ph and all.

[Minty]

Hey Grumpy Mate,

Nice write up dude, that must have taken you fudging ages! and either your real good at typing or you proof read that shit at least 10 times

1) Concentrations of dissolved oxygen (DO).

Although water is made up of hydrogen and oxygen, some oxygen atoms hang about in-between the water molecules. This is what we call dissolved oxygen. These oxygen atoms are what keep the water healthy. Plants will get most of their oxygen from photosynthesis but dissolved oxygen is important for aerobic respiration as well as keeping the aerobic bacteria healthy. In hydroponics, the DO will help keep the roots strong and healthy. If a plant doesn’t have enough DO in hydroponics, the roots will become damaged, osmosis is effected and the plant cannot take up enough water. It also causes the aerobic bacteria to die and anerobic bacteria can thrive and cause root rot. In soil, the microlife that feeds the plants also make use of the DO.

So on this note would you say it is worth 'knowing/recording/etc' the DO levels? I do (no pune intended) have a spare isolated circuit in my build so could easily accommodate a DO probe but for a price of £250+ is it really something you would benefit from / need to know that precisely (such as you do for pH)? I assume once you know the levels you can adjust by adding more air to the water but how would you go about bring the levels down (apart from obviously stopping adding any additional air)?

cannabis is a very active and hungry plant and needs at least 200ppm of Ca and 60ppm Mg for healthy growth in optimal conditions

Thanks, Wrote that shit down in my little book (go figure, I still use paper until I finish the software for it).

We’ve gone off on a tangent for a little bit here but it’s all relevant to the title in this post. Now you’ve read all the above, are you still considering reverse osmosis water? Maybe you have other issues, take your water from another source than the supply to your property or your water is like mine and is so hard you need to buy a new kettle every few months, you may want to consider reverse osmosis. The reason why I started part one like this is because 99% of you out there shouldn’t even be considering reverse osmosis. Bottom line is reverse osmosis comes with it's own set of issues and your tap water will grow great cannabis. For the rest of you, reverse osmosis brings a whole host of benefits like being in total control of your water, less bicarb build up, less chances of bacterial or viral infections and also some downsides. In part two of this write-up, I’ll go deeper into the details of the benefits and caveats of using reverse osmosis water for growing cannabis.

OK, so I have read the complete post twice and I still don't know if R.O. water is better or worse for me,
considering the following points:-

• Growing in Hydroponics R-DWC
• Auto Dosing so having a known starting point makes things easier
• R.O. currently feeds both the main tank and the DIY Humidifier
• I have already purchased the R.O. Water filter
• I have both mains pressure water and R.O. Water feeds directly above the Tank.

The more I see this topic mentioned the more people are suggesting R.O. is not required and even not recommended. I don't have a problem ditching the R.O. filter or just using it for supplying the De-Humidifier etc.

I guess for my first build/grow, I kinda wanna try things out and while not wishing to make mistakes I feel they are worthwhile in the long run for the learning curve aspect.

[Josh]

Hey Grumpy Mate,

Nice write up dude, that must have taken you fudging ages! and either your real good at typing or you proof read that shit at least 10 times

1) Concentrations of dissolved oxygen (DO).

Although water is made up of hydrogen and oxygen, some oxygen atoms hang about in-between the water molecules. This is what we call dissolved oxygen. These oxygen atoms are what keep the water healthy. Plants will get most of their oxygen from photosynthesis but dissolved oxygen is important for aerobic respiration as well as keeping the aerobic bacteria healthy. In hydroponics, the DO will help keep the roots strong and healthy. If a plant doesn’t have enough DO in hydroponics, the roots will become damaged, osmosis is effected and the plant cannot take up enough water. It also causes the aerobic bacteria to die and anerobic bacteria can thrive and cause root rot. In soil, the microlife that feeds the plants also make use of the DO.

So on this note would you say it is worth 'knowing/recording/etc' the DO levels? I do (no pune intended) have a spare isolated circuit in my build so could easily accommodate a DO probe but for a price of £250+ is it really something you would benefit from / need to know that precisely (such as you do for pH)? I assume once you know the levels you can adjust by adding more air to the water but how would you go about bring the levels down (apart from obviously stopping adding any additional air)?

cannabis is a very active and hungry plant and needs at least 200ppm of Ca and 60ppm Mg for healthy growth in optimal conditions

Thanks, Wrote that shit down in my little book (go figure, I still use paper until I finish the software for it).

We’ve gone off on a tangent for a little bit here but it’s all relevant to the title in this post. Now you’ve read all the above, are you still considering reverse osmosis water? Maybe you have other issues, take your water from another source than the supply to your property or your water is like mine and is so hard you need to buy a new kettle every few months, you may want to consider reverse osmosis. The reason why I started part one like this is because 99% of you out there shouldn’t even be considering reverse osmosis. Bottom line is reverse osmosis comes with it's own set of issues and your tap water will grow great cannabis. For the rest of you, reverse osmosis brings a whole host of benefits like being in total control of your water, less bicarb build up, less chances of bacterial or viral infections and also some downsides. In part two of this write-up, I’ll go deeper into the details of the benefits and caveats of using reverse osmosis water for growing cannabis.

OK, so I have read the complete post twice and I still don't know if R.O. water is better or worse for me,
considering the following points:-

• Growing in Hydroponics R-DWC
• Auto Dosing so having a known starting point makes things easier
• R.O. currently feeds both the main tank and the DIY Humidifier
• I have already purchased the R.O. Water filter
• I have both mains pressure water and R.O. Water feeds directly above the Tank.

The more I see this topic mentioned the more people are suggesting R.O. is not required and even not recommended. I don't have a problem ditching the R.O. filter or just using it for supplying the De-Humidifier etc.

I guess for my first build/grow, I kinda wanna try things out and while not wishing to make mistakes I feel they are worthwhile in the long run for the learning curve aspect.

RO water is just hard to buffer imo. Ph will be all over the place in dwc unless you get your nutes dialed perfect. A doser would solve this of course, but I like to set my ph and not have to add any more

I've heard of ph perfect nutrients but I never got around to giving them a shot. I just switched to tap water and problem was solved

Sent from my LGMP260 using Tapatalk

[seymore_budz]

I’m very new, but I’m looking for a “ constant” in my water. So when I mix my nutes I know what to expect ph and all.

Water will become more stable as you add more nutrients because this increases the buffering capacity. Calcium Carbonate had a high buffering capacity so if your water is very hard, it will take a lot of acid to reduce the PH but it will be the most stable and predictable. This question is quite ambiguous though, do you mean stable as in mixing time or stable as in constant as the plants feed? If you mean the latter, that's a completely different subject and if people would like, I could cover that too in another post?

Thanks for sharing!

No worries TTL, lockdown got me writing posts :)

Love the write-up man well done

The only thing I have a different opinion on is when you said -
"Most nutrients have been formulated to fit the profile of the water"

I think most companies formulate their recipes for RO water, easier for the results to be consistent with growers. Because as you stated, tap is different everywhere you go

Unless that's what you meant, then ignore me really high atm

Sent from my LGMP260 using Tapatalk

Thanks Integrajosh! I'm not sure if it's different across the water but in the UK and within the hobby hydro market, most nutrients come in a hard and soft water variant. I'm pretty sure most nutrients that specify soft water would be suitable for RO in most situations but cannabis does love it's calcium. The trouble is with calcium is it's linked to transpiration! It's quite common in indoor because of the lack of control over HVAC for many cannabis growers as we have to be stealthy and keep things compact. Lack of air movement and hot temperatures can manifest into calcium def. There is actually more to consider like a the relationship between calcium and magnesium and optimal ratios of the two but that's getting a little deep for me. I'm still learning here too so can't explain it all but I've read the optimal ratio is 8:1 Ca to Mg? It would indeed be so much easier for manufacturers if everyonr used RO as you're starting with a blank slate.

Hey Grumpy Mate,

Nice write up dude, that must have taken you fudging ages! and either your real good at typing or you proof read that shit at least 10 times

1) Concentrations of dissolved oxygen (DO).

Although water is made up of hydrogen and oxygen, some oxygen atoms hang about in-between the water molecules. This is what we call dissolved oxygen. These oxygen atoms are what keep the water healthy. Plants will get most of their oxygen from photosynthesis but dissolved oxygen is important for aerobic respiration as well as keeping the aerobic bacteria healthy. In hydroponics, the DO will help keep the roots strong and healthy. If a plant doesn’t have enough DO in hydroponics, the roots will become damaged, osmosis is effected and the plant cannot take up enough water. It also causes the aerobic bacteria to die and anerobic bacteria can thrive and cause root rot. In soil, the microlife that feeds the plants also make use of the DO.

So on this note would you say it is worth 'knowing/recording/etc' the DO levels? I do (no pune intended) have a spare isolated circuit in my build so could easily accommodate a DO probe but for a price of £250+ is it really something you would benefit from / need to know that precisely (such as you do for pH)? I assume once you know the levels you can adjust by adding more air to the water but how would you go about bring the levels down (apart from obviously stopping adding any additional air)?

cannabis is a very active and hungry plant and needs at least 200ppm of Ca and 60ppm Mg for healthy growth in optimal conditions

Thanks, Wrote that shit down in my little book (go figure, I still use paper until I finish the software for it).

We’ve gone off on a tangent for a little bit here but it’s all relevant to the title in this post. Now you’ve read all the above, are you still considering reverse osmosis water? Maybe you have other issues, take your water from another source than the supply to your property or your water is like mine and is so hard you need to buy a new kettle every few months, you may want to consider reverse osmosis. The reason why I started part one like this is because 99% of you out there shouldn’t even be considering reverse osmosis. Bottom line is reverse osmosis comes with it's own set of issues and your tap water will grow great cannabis. For the rest of you, reverse osmosis brings a whole host of benefits like being in total control of your water, less bicarb build up, less chances of bacterial or viral infections and also some downsides. In part two of this write-up, I’ll go deeper into the details of the benefits and caveats of using reverse osmosis water for growing cannabis.

OK, so I have read the complete post twice and I still don't know if R.O. water is better or worse for me,
considering the following points:-

• Growing in Hydroponics R-DWC
• Auto Dosing so having a known starting point makes things easier
• R.O. currently feeds both the main tank and the DIY Humidifier
• I have already purchased the R.O. Water filter
• I have both mains pressure water and R.O. Water feeds directly above the Tank.

The more I see this topic mentioned the more people are suggesting R.O. is not required and even not recommended. I don't have a problem ditching the R.O. filter or just using it for supplying the De-Humidifier etc.

I guess for my first build/grow, I kinda wanna try things out and while not wishing to make mistakes I feel they are worthwhile in the long run for the learning curve aspect.

Thanks Minty, I actually taught myself to type about a year ago. I've been a computer engineer for nearly 20 years and couldn't type for shit. When I started, I was sitting around 20wpm and looking down. In about 3 months, I was sitting around 40wpm and now I'm hovering around 60-70wpm. Definitely a skill worth learning as when writing larger things, you don't have to think about typing as it's a natural as talking.

Saying all that, I'm on my phone now so that slows me down a bit lol. In regards to DO levels in the water, it's nice to know but far from required. As long as you have good movement of water and keep the temps below 28C, you can confidently say you have plenty :)

In regards to should you use RO water, I'll cover this in more details in part two. The reason why I split the article into two parts is because reverse osmosis is far from required to grow good weed and there's lots of misinformation around that influence peoples decisions. I wanted to make it clear that RO os far from essential and can make things worse if you don't understand RO water and how to use it. But the quick version is RO is like giving a grower the tools to bring out the best in your grows and in the right hands can bring a host of benefits but also has it's downsides and is also handing you a loaded gun for you to shoot yourself in the foot :) As a beginner, I would normally advise against it but judging by the level of detail I've seen you pile into your projects I think you will do well with RO and tripart Minty.

RO water is just hard to buffer imo. Ph will be all over the place in dwc unless you get your nutes dialed perfect. A doser would solve this of course, but I like to set my ph and not have to add any more

I've heard of ph perfect nutrients but I never got around to giving them a shot. I just switched to tap water and problem was solved

RO water has zero buffer. Again, this is better saved for part 2 but RO is PH neutral but without any buffer, RO water is unstable. When you initially mix up, your water will drop rapidly as it assumes the PH of the bottled nutrients and then you have to bring it up. Once mixed, it's actually quite stable with some very big caveats! As the plants and mocrolife use the nutrients, the PH will change. Saying that, this can be easily buffered by additional additives like humic acid and other agents that will balance things out. PH perfect was at first mistaken for the same thing but it's completely different. How PH perfect works (from memory so correct me if I'm wrong Josh) is it's been formulated for RO water and contains a specific formulation that guarantees that the PH will be the same when mixed at the correct levels and not a buffer to compensate for biological activity in the system. And it doesn't work in hard water :) they have always stated to get the most out of their range, you need to use pure RO water.

[Josh]

I’m very new, but I’m looking for a “ constant” in my water. So when I mix my nutes I know what to expect ph and all.

Water will become more stable as you add more nutrients because this increases the buffering capacity. Calcium Carbonate had a high buffering capacity so if your water is very hard, it will take a lot of acid to reduce the PH but it will be the most stable and predictable. This question is quite ambiguous though, do you mean stable as in mixing time or stable as in constant as the plants feed? If you mean the latter, that's a completely different subject and if people would like, I could cover that too in another post?

Thanks for sharing!

No worries TTL, lockdown got me writing posts :)

Love the write-up man well done

The only thing I have a different opinion on is when you said -
"Most nutrients have been formulated to fit the profile of the water"

I think most companies formulate their recipes for RO water, easier for the results to be consistent with growers. Because as you stated, tap is different everywhere you go

Unless that's what you meant, then ignore me really high atm

Sent from my LGMP260 using Tapatalk

Thanks Integrajosh! I'm not sure if it's different across the water but in the UK and within the hobby hydro market, most nutrients come in a hard and soft water variant. I'm pretty sure most nutrients that specify soft water would be suitable for RO in most situations but cannabis does love it's calcium. The trouble is with calcium is it's linked to transpiration! It's quite common in indoor because of the lack of control over HVAC for many cannabis growers as we have to be stealthy and keep things compact. Lack of air movement and hot temperatures can manifest into calcium def. There is actually more to consider like a the relationship between calcium and magnesium and optimal ratios of the two but that's getting a little deep for me. I'm still learning here too so can't explain it all but I've read the optimal ratio is 8:1 Ca to Mg? It would indeed be so much easier for manufacturers if everyonr used RO as you're starting with a blank slate.

Hey Grumpy Mate,

Nice write up dude, that must have taken you fudging ages! and either your real good at typing or you proof read that shit at least 10 times

1) Concentrations of dissolved oxygen (DO).

Although water is made up of hydrogen and oxygen, some oxygen atoms hang about in-between the water molecules. This is what we call dissolved oxygen. These oxygen atoms are what keep the water healthy. Plants will get most of their oxygen from photosynthesis but dissolved oxygen is important for aerobic respiration as well as keeping the aerobic bacteria healthy. In hydroponics, the DO will help keep the roots strong and healthy. If a plant doesn’t have enough DO in hydroponics, the roots will become damaged, osmosis is effected and the plant cannot take up enough water. It also causes the aerobic bacteria to die and anerobic bacteria can thrive and cause root rot. In soil, the microlife that feeds the plants also make use of the DO.

So on this note would you say it is worth 'knowing/recording/etc' the DO levels? I do (no pune intended) have a spare isolated circuit in my build so could easily accommodate a DO probe but for a price of £250+ is it really something you would benefit from / need to know that precisely (such as you do for pH)? I assume once you know the levels you can adjust by adding more air to the water but how would you go about bring the levels down (apart from obviously stopping adding any additional air)?

cannabis is a very active and hungry plant and needs at least 200ppm of Ca and 60ppm Mg for healthy growth in optimal conditions

Thanks, Wrote that shit down in my little book (go figure, I still use paper until I finish the software for it).

We’ve gone off on a tangent for a little bit here but it’s all relevant to the title in this post. Now you’ve read all the above, are you still considering reverse osmosis water? Maybe you have other issues, take your water from another source than the supply to your property or your water is like mine and is so hard you need to buy a new kettle every few months, you may want to consider reverse osmosis. The reason why I started part one like this is because 99% of you out there shouldn’t even be considering reverse osmosis. Bottom line is reverse osmosis comes with it's own set of issues and your tap water will grow great cannabis. For the rest of you, reverse osmosis brings a whole host of benefits like being in total control of your water, less bicarb build up, less chances of bacterial or viral infections and also some downsides. In part two of this write-up, I’ll go deeper into the details of the benefits and caveats of using reverse osmosis water for growing cannabis.

OK, so I have read the complete post twice and I still don't know if R.O. water is better or worse for me,
considering the following points:-

• Growing in Hydroponics R-DWC
• Auto Dosing so having a known starting point makes things easier
• R.O. currently feeds both the main tank and the DIY Humidifier
• I have already purchased the R.O. Water filter
• I have both mains pressure water and R.O. Water feeds directly above the Tank.

The more I see this topic mentioned the more people are suggesting R.O. is not required and even not recommended. I don't have a problem ditching the R.O. filter or just using it for supplying the De-Humidifier etc.

I guess for my first build/grow, I kinda wanna try things out and while not wishing to make mistakes I feel they are worthwhile in the long run for the learning curve aspect.

Thanks Minty, I actually taught myself to type about a year ago. I've been a computer engineer for nearly 20 years and couldn't type for shit. When I started, I was sitting around 20wpm and looking down. In about 3 months, I was sitting around 40wpm and now I'm hovering around 60-70wpm. Definitely a skill worth learning as when writing larger things, you don't have to think about typing as it's a natural as talking.

Saying all that, I'm on my phone now so that slows me down a bit lol. In regards to DO levels in the water, it's nice to know but far from required. As long as you have good movement of water and keep the temps below 28C, you can confidently say you have plenty :)

In regards to should you use RO water, I'll cover this in more details in part two. The reason why I split the article into two parts is because reverse osmosis is far from required to grow good weed and there's lots of misinformation around that influence peoples decisions. I wanted to make it clear that RO os far from essential and can make things worse if you don't understand RO water and how to use it. But the quick version is RO is like giving a grower the tools to bring out the best in your grows and in the right hands can bring a host of benefits but also has it's downsides and is also handing you a loaded gun for you to shoot yourself in the foot :) As a beginner, I would normally advise against it but judging by the level of detail I've seen you pile into your projects I think you will do well with RO and tripart Minty.

RO water is just hard to buffer imo. Ph will be all over the place in dwc unless you get your nutes dialed perfect. A doser would solve this of course, but I like to set my ph and not have to add any more

I've heard of ph perfect nutrients but I never got around to giving them a shot. I just switched to tap water and problem was solved

RO water has zero buffer. Again, this is better saved for part 2 but RO is PH neutral but without any buffer, RO water is unstable. When you initially mix up, your water will drop rapidly as it assumes the PH of the bottled nutrients and then you have to bring it up. Once mixed, it's actually quite stable with some very big caveats! As the plants and mocrolife use the nutrients, the PH will change. Saying that, this can be easily buffered by additional additives like humic acid and other agents that will balance things out. PH perfect was at first mistaken for the same thing but it's completely different. How PH perfect works (from memory so correct me if I'm wrong Josh) is it's been formulated for RO water and contains a specific formulation that guarantees that the PH will be the same when mixed at the correct levels and not a buffer to compensate for biological activity in the system. And it doesn't work in hard water :) they have always stated to get the most out of their range, you need to use pure RO water.

Sry bro, but from years of trial and error I gotta disagree with you still. Lmaoo

Cannabis plants aren't calcium whores like tomatoes, I realise that every environment is different and environmental factors can manifest into deficiencies (like you mentioned) but the solution is to fix your environment, not figure out the perfect ratio of cal to mag or switch to RO on a whim

Proper night and day time temps, proper night and day time humidity, good air movement, good air exchange

Also keep in mind that if you supplement co2, this will rapidly lower the ph of a mix using RO water. I switched to tap and the issue is gone, no more ph diving overnight.
I can keep my air pumps in the same room again, which is awesome. 1500 ppm of co2.
Same nutes, same additives, only difference is switching to tap

I realise that some people have crazy water, like yourself, but like you said for 99% of growers it's unnecessary and causes issues

Sent from my LGMP260 using Tapatalk

[seymore_budz]

I’m very new, but I’m looking for a “ constant” in my water. So when I mix my nutes I know what to expect ph and all.

Water will become more stable as you add more nutrients because this increases the buffering capacity. Calcium Carbonate had a high buffering capacity so if your water is very hard, it will take a lot of acid to reduce the PH but it will be the most stable and predictable. This question is quite ambiguous though, do you mean stable as in mixing time or stable as in constant as the plants feed? If you mean the latter, that's a completely different subject and if people would like, I could cover that too in another post?

Thanks for sharing!

No worries TTL, lockdown got me writing posts :)

Love the write-up man well done

The only thing I have a different opinion on is when you said -
"Most nutrients have been formulated to fit the profile of the water"

I think most companies formulate their recipes for RO water, easier for the results to be consistent with growers. Because as you stated, tap is different everywhere you go

Unless that's what you meant, then ignore me really high atm

Sent from my LGMP260 using Tapatalk

Thanks Integrajosh! I'm not sure if it's different across the water but in the UK and within the hobby hydro market, most nutrients come in a hard and soft water variant. I'm pretty sure most nutrients that specify soft water would be suitable for RO in most situations but cannabis does love it's calcium. The trouble is with calcium is it's linked to transpiration! It's quite common in indoor because of the lack of control over HVAC for many cannabis growers as we have to be stealthy and keep things compact. Lack of air movement and hot temperatures can manifest into calcium def. There is actually more to consider like a the relationship between calcium and magnesium and optimal ratios of the two but that's getting a little deep for me. I'm still learning here too so can't explain it all but I've read the optimal ratio is 8:1 Ca to Mg? It would indeed be so much easier for manufacturers if everyonr used RO as you're starting with a blank slate.

Hey Grumpy Mate,

Nice write up dude, that must have taken you fudging ages! and either your real good at typing or you proof read that shit at least 10 times



So on this note would you say it is worth 'knowing/recording/etc' the DO levels? I do (no pune intended) have a spare isolated circuit in my build so could easily accommodate a DO probe but for a price of £250+ is it really something you would benefit from / need to know that precisely (such as you do for pH)? I assume once you know the levels you can adjust by adding more air to the water but how would you go about bring the levels down (apart from obviously stopping adding any additional air)?



Thanks, Wrote that shit down in my little book (go figure, I still use paper until I finish the software for it).



OK, so I have read the complete post twice and I still don't know if R.O. water is better or worse for me,
considering the following points:-

• Growing in Hydroponics R-DWC
• Auto Dosing so having a known starting point makes things easier
• R.O. currently feeds both the main tank and the DIY Humidifier
• I have already purchased the R.O. Water filter
• I have both mains pressure water and R.O. Water feeds directly above the Tank.

The more I see this topic mentioned the more people are suggesting R.O. is not required and even not recommended. I don't have a problem ditching the R.O. filter or just using it for supplying the De-Humidifier etc.

I guess for my first build/grow, I kinda wanna try things out and while not wishing to make mistakes I feel they are worthwhile in the long run for the learning curve aspect.

Thanks Minty, I actually taught myself to type about a year ago. I've been a computer engineer for nearly 20 years and couldn't type for shit. When I started, I was sitting around 20wpm and looking down. In about 3 months, I was sitting around 40wpm and now I'm hovering around 60-70wpm. Definitely a skill worth learning as when writing larger things, you don't have to think about typing as it's a natural as talking.

Saying all that, I'm on my phone now so that slows me down a bit lol. In regards to DO levels in the water, it's nice to know but far from required. As long as you have good movement of water and keep the temps below 28C, you can confidently say you have plenty :)

In regards to should you use RO water, I'll cover this in more details in part two. The reason why I split the article into two parts is because reverse osmosis is far from required to grow good weed and there's lots of misinformation around that influence peoples decisions. I wanted to make it clear that RO os far from essential and can make things worse if you don't understand RO water and how to use it. But the quick version is RO is like giving a grower the tools to bring out the best in your grows and in the right hands can bring a host of benefits but also has it's downsides and is also handing you a loaded gun for you to shoot yourself in the foot :) As a beginner, I would normally advise against it but judging by the level of detail I've seen you pile into your projects I think you will do well with RO and tripart Minty.

RO water is just hard to buffer imo. Ph will be all over the place in dwc unless you get your nutes dialed perfect. A doser would solve this of course, but I like to set my ph and not have to add any more

I've heard of ph perfect nutrients but I never got around to giving them a shot. I just switched to tap water and problem was solved

RO water has zero buffer. Again, this is better saved for part 2 but RO is PH neutral but without any buffer, RO water is unstable. When you initially mix up, your water will drop rapidly as it assumes the PH of the bottled nutrients and then you have to bring it up. Once mixed, it's actually quite stable with some very big caveats! As the plants and mocrolife use the nutrients, the PH will change. Saying that, this can be easily buffered by additional additives like humic acid and other agents that will balance things out. PH perfect was at first mistaken for the same thing but it's completely different. How PH perfect works (from memory so correct me if I'm wrong Josh) is it's been formulated for RO water and contains a specific formulation that guarantees that the PH will be the same when mixed at the correct levels and not a buffer to compensate for biological activity in the system. And it doesn't work in hard water :) they have always stated to get the most out of their range, you need to use pure RO water.

Sry bro, but from years of trial and error I gotta disagree with you still. Lmaoo

Cannabis plants aren't calcium whores like tomatoes, I realise that every environment is different and environmental factors can manifest into deficiencies (like you mentioned) but the solution is to fix your environment, not figure out the perfect ratio of cal to mag or switch to RO on a whim

Proper night and day time temps, proper night and day time humidity, good air movement, good air exchange

Also keep in mind that if you supplement co2, this will rapidly lower the ph of a mix using RO water. I switched to tap and the issue is gone, no more ph diving overnight.
I can keep my air pumps in the same room again, which is awesome. 1500 ppm of co2.
Same nutes, same additives, only difference is switching to tap

I realise that some people have crazy water, like yourself, but like you said for 99% of growers it's unnecessary nd causes issues

Sent from my LGMP260 using Tapatalk

Thanks for the feedback Josh! It's good to disagree and hear others experiences. I'm not saying you can push the TDS up to the levels tomatoes can gobble up but cannabis ain't no slouch when it comes to gobbling up the calcium.

I also think that the levels don't have to be as accurate as people think. My feelings are the plant will take what it requires as long as it has enough reserve. Ratios and absence are more important if we're talking about nutrient formulas.

The reason why you see a drop in your PH when using CO2 with RO and airstones is your airstones are pushing CO2 into the water and that reacts with the water and creates weak carbonic acid (H2CO3). The reason why this doesn't affect you so much with tap water is you have more calcium carbonate to buffer the reaction. Calcium carbonate is a very good buffer. :) don't use airstones with RO :)

[Josh]

Water will become more stable as you add more nutrients because this increases the buffering capacity. Calcium Carbonate had a high buffering capacity so if your water is very hard, it will take a lot of acid to reduce the PH but it will be the most stable and predictable. This question is quite ambiguous though, do you mean stable as in mixing time or stable as in constant as the plants feed? If you mean the latter, that's a completely different subject and if people would like, I could cover that too in another post?
No worries TTL, lockdown got me writing posts :)
Thanks Integrajosh! I'm not sure if it's different across the water but in the UK and within the hobby hydro market, most nutrients come in a hard and soft water variant. I'm pretty sure most nutrients that specify soft water would be suitable for RO in most situations but cannabis does love it's calcium. The trouble is with calcium is it's linked to transpiration! It's quite common in indoor because of the lack of control over HVAC for many cannabis growers as we have to be stealthy and keep things compact. Lack of air movement and hot temperatures can manifest into calcium def. There is actually more to consider like a the relationship between calcium and magnesium and optimal ratios of the two but that's getting a little deep for me. I'm still learning here too so can't explain it all but I've read the optimal ratio is 8:1 Ca to Mg? It would indeed be so much easier for manufacturers if everyonr used RO as you're starting with a blank slate.
Thanks Minty, I actually taught myself to type about a year ago. I've been a computer engineer for nearly 20 years and couldn't type for shit. When I started, I was sitting around 20wpm and looking down. In about 3 months, I was sitting around 40wpm and now I'm hovering around 60-70wpm. Definitely a skill worth learning as when writing larger things, you don't have to think about typing as it's a natural as talking.

Saying all that, I'm on my phone now so that slows me down a bit lol. In regards to DO levels in the water, it's nice to know but far from required. As long as you have good movement of water and keep the temps below 28C, you can confidently say you have plenty :)

In regards to should you use RO water, I'll cover this in more details in part two. The reason why I split the article into two parts is because reverse osmosis is far from required to grow good weed and there's lots of misinformation around that influence peoples decisions. I wanted to make it clear that RO os far from essential and can make things worse if you don't understand RO water and how to use it. But the quick version is RO is like giving a grower the tools to bring out the best in your grows and in the right hands can bring a host of benefits but also has it's downsides and is also handing you a loaded gun for you to shoot yourself in the foot :) As a beginner, I would normally advise against it but judging by the level of detail I've seen you pile into your projects I think you will do well with RO and tripart Minty.
RO water has zero buffer. Again, this is better saved for part 2 but RO is PH neutral but without any buffer, RO water is unstable. When you initially mix up, your water will drop rapidly as it assumes the PH of the bottled nutrients and then you have to bring it up. Once mixed, it's actually quite stable with some very big caveats! As the plants and mocrolife use the nutrients, the PH will change. Saying that, this can be easily buffered by additional additives like humic acid and other agents that will balance things out. PH perfect was at first mistaken for the same thing but it's completely different. How PH perfect works (from memory so correct me if I'm wrong Josh) is it's been formulated for RO water and contains a specific formulation that guarantees that the PH will be the same when mixed at the correct levels and not a buffer to compensate for biological activity in the system. And it doesn't work in hard water :) they have always stated to get the most out of their range, you need to use pure RO water.

Sry bro, but from years of trial and error I gotta disagree with you still. Lmaoo

Cannabis plants aren't calcium whores like tomatoes, I realise that every environment is different and environmental factors can manifest into deficiencies (like you mentioned) but the solution is to fix your environment, not figure out the perfect ratio of cal to mag or switch to RO on a whim

Proper night and day time temps, proper night and day time humidity, good air movement, good air exchange

Also keep in mind that if you supplement co2, this will rapidly lower the ph of a mix using RO water. I switched to tap and the issue is gone, no more ph diving overnight.
I can keep my air pumps in the same room again, which is awesome. 1500 ppm of co2.
Same nutes, same additives, only difference is switching to tap

I realise that some people have crazy water, like yourself, but like you said for 99% of growers it's unnecessary nd causes issues

Sent from my LGMP260 using Tapatalk

Thanks for the feedback Josh! It's good to disagree and hear others experiences. I'm not saying you can push the TDS up to the levels tomatoes can gobble up but cannabis ain't no slouch when it comes to gobbling up the calcium.

I also think that the levels don't have to be as accurate as people think. My feelings are the plant will take what it requires as long as it has enough reserve. Ratios and absence are more important if we're talking about nutrient formulas.

The reason why you see a drop in your PH when using CO2 with RO and airstones is your airstones are pushing CO2 into the water and that reacts with the water and creates weak carbonic acid (H2CO3). The reason why this doesn't affect you so much with tap water is you have more calcium carbonate to buffer the reaction. Calcium carbonate is a very good buffer. :) don't use airstones with RO :)

What's the point of this thread bro? You trying to convince people to use RO, not use it, or just have a discussion about water in general?
I'm confused

Sent from my LGMP260 using Tapatalk