Discussion - Nutrient schedules and regimes

[seymore_budz]

Hello GR420,

Just recently I embarked on a journey to expand my knowledge around hydroponic nutrient recipes and how they're formulated for different species. Throughout this process, it became apparent that some of the generalised grow schedules supplied by the nutrient manufacturers are quite specific on application rates etc and this often leads to a misunderstanding around nutrient requirements and a mistrust in these schedules. In many cases, the end user wasn't overfeeding in general, but they had the wrong environmental conditions or threw a whole bunch of additives in that upset the ratio of different elements.

Most hobby growers, if asked, wouldn't dare feed their plants with a full-strengh dose of nutrients according to the manufacturers guidelines. You'll also find lots of growers chasing their tail increasing and decreasing fertiliser strength to correct an issue and end up exacerbating the issue.

As growers mature, they will learn that feed strengh isn't a one size fits all and depends on multiple factors from environmental factors to cultivar. This made me think, what could nutrient suppliers do to fix this issue?

Well, it's 2023! And everyone has a smartphone in their pocket. Surely they could make an app that you could install on your phone and plug in parameters relating to environment etc and have the app calculate a more accurate feeding regime? This could also serve as a diagnosis tool where suppliers could peek at your conditions and make suggestions based on data provided.

If a nutrient company released an app to compliment their range of fertiliser that could do the above, would you use it?

[Grumpy Toad]

I was that grower that struggled with feed schedules. Feeding nutes at full recommended strength led to severe leaf burning. While that may have been due to a number of things I was convinced it was over feeding. Reading up on the web or books led me to believe that nutrient companies were out to sell more product and recommended more than what was needed. I've only used two nutrient lines since starting to grow about 4-1/2 years ago. I have always grown multiple strains at once. So it is easy to see that each plant (not just cultivar) has it's own "sweet spot". But I think that you can find a general medium mix that will probably hit most plant's needs and the outliers will be the exception. If your grow is a a level that you are chasing the outliers then a one size fits all app probably wouldn't be helpful. I have to wonder though, if your plants are doing well at 1.2 EC while the manufacturer recommends 2.2 EC (and the plants do well at that level as well) are we wasting unused nutrients?

I look at growing like it is a mobile art hanging.



It will all sit stable until you change one things then everything is now affected. So these days my main focus is consistency. I will only make 1 or 2 changes from grow to grow. Otherwise I don't know what works or doesn't.

But to answer your question, I would give an app a try. If it wasn't flexible enough to fit my grow then it would quickly go by the wayside.

[2-Scoops]

I think a quite lot is known and understood more about VPD these days, well the environment as a whole and if you had that bang on all time maybe it would be a different ball game with our fert strengths as plants would prolly take up lots more without any fuss. That said I'm a bit of the old school thinking and I'm a big believer in you cant beat what yours plants are telling you, when you look and if the plants are looking happy and are lush green all over your golden. I also think quite a lot is down to experience we gain as growers along the way, stuff like what temps or humidity is needed at that time to lets say sort out a potential problem and help the plants with more uptake or less uptake of ferts and if a higher or lower EC is needed cus of this. You really don't need summink telling you this, that & other is bang on except the plants imo

When i first started out growing indoors, for years i used to feed full size vegging plants 1.8 to 2.2 EC and flowering plants 2.8ec all the way without any problems although i had to flush the 25ltr pots right back on a weekly basis as run off was hitting 4 and 5+ sometimes, i now know lots more and that i was pissing money down the drain. I now feed vegging plants anything between 1.0 to 1.2ec and flowering plants from 1.2 to 1.6 EC and theirs no need for weekly flush of pots and the plants are generally always a lush green from top to bottom. Theirs lots of different scenarios as to how long a fert strength can be used for without causing plant problems or not, like if your running bigger pots you can feed a lot higher EC for a lot longer without hitting problems than you could if you were running same feeds in much smaller pots, each size pot will have its own saturation level of fert salts before it starts going tits up causing for your plants, that also applies different grow mediums as well.

Basically theirs lots of different scenarios to take in to account when growing and feeding right strength, its not just black and white on back of a bottle which i always tell peeps that is just a general guide. I think most growers will find if they're using salt base A&B type ferts they will generally find a simple feed regime that works well for all weed plants or strains pretty quickly without much faff, although even A&B can still be played around with out causing too much drama for the plant if grower feels need to. I cant really comment on other type ferts.

[seymore_budz]

Thanks for your input guys. I've been working on a POC of the tool described. Nothing worth sharing yet, but it has a whole bunch of recipes for different nutrient suppliers and can calculate optimal ratios based on the size and stage of the plants and will adjust for VPD. You plug in the light size, power, target DLI and your room stats like temperature, humidity, leaf temperature etc and it spits out the correct amount of each component to add to a reservoir as v/v and w/v.

It can only guess as you'd need to create a constant feedback loop of some sort to achieve that, but it will get you in the ballpark range. Also displays each element as elemental PPM, so a grower can say with confidence that they don't have X deficiency.

The chemistry and math is quite hard and I've never gone this deep before. Been like going back to school :)

The reason why I asked is because I'm considering building something user friendly and maybe releasing as an opensource project where people can collaborate. There's no reason why I couldn't add soil and organic recipes, albeit you wouldn't have the level of precision you would have with hydroponics. You probably couldn't adjust fast enough to keep up unless you was using something very inert. I could add soil recipes though to suit a hot garden or for a hungry cultivar. Kind of like a 21st century pocketbook.

You could take things to the next level and hook up your environmental controller and have the tool guesstimate the amounts to add based on a weeks data maybe? The math becomes even more complex then *welp*

Another issue I've run into that not all nutrient suppliers tell the truth about their guaranteed analysis. They only have to meet the minimum, and a lot of the time, it's a lot more. You'd have to reverse engineer the worst offenders solution to be accurate. And then we're into IP territory. I don't want to end up in court.

[seymore_budz]

When i first started out growing indoors, for years i used to feed full size vegging plants 1.8 to 2.2 EC and flowering plants 2.8ec all the way without any problems although i had to flush the 25ltr pots right back on a weekly basis as run off was hitting 4 and 5+ sometimes, i now know lots more and that i was pissing money down the drain. I now feed vegging plants anything between 1.0 to 1.2ec and flowering plants from 1.2 to 1.6 EC and theirs no need for weekly flush of pots and the plants are generally always a lush green from top to bottom.

The trouble with EC is it doesn't really tell you a lot. Of course there's an upper limit because you can only get an idea to what's in solution. Different nutrients will be derived from different sources and will have a completely different EC when within range. I think this is where some of the confusion lays (it did with me). You see a grower running super high EC using product X so you try the same EC with product Y and burn the shit out of the plants

[2-Scoops]

Another issue I've run into that not all nutrient suppliers tell the truth about their guaranteed analysis. They only have to meet the minimum, and a lot of the time, it's a lot more.

Do you know its a real snakey game in countries like UK, is the weed fert game. I'm not even sure fert makers would have to meet any sort of standards in countries like Britain, cus growing weed is illegal i would think weed specific fert game is an unregulated industry too, stuff that is being sold as weed base ferts wont actually come under the same laws or rules and regulations as lets say normal off the shelf tomato feed. A good example is dodgy PGR`s in certain boosts I'm pretty sure these wouldn`t make it to shelf over the pond in States. What do you recon mate ?

Thanks for your input guys. I've been working on a POC of the tool described. Nothing worth sharing yet, but it has a whole bunch of recipes for different nutrient suppliers and can calculate optimal ratios based on the size and stage of the plants and will adjust for VPD. You plug in the light size, power, target DLI and your room stats like temperature, humidity, leaf temperature etc and it spits out the correct amount of each component to add to a reservoir as v/v and w/v.

It can only guess as you'd need to create a constant feedback loop of some sort to achieve that, but it will get you in the ballpark range. Also displays each element as elemental PPM, so a grower can say with confidence that they don't have X deficiency.

Seems a good idea especially for helping newer growers out.

[seymore_budz]

Another issue I've run into that not all nutrient suppliers tell the truth about their guaranteed analysis. They only have to meet the minimum, and a lot of the time, it's a lot more.

Do you know its a real snakey game in countries like UK, is the weed fert game. I'm not even sure fert makers would have to meet any sort of standards in countries like Britain, cus growing weed is illegal i would think weed specific fert game is an unregulated industry too, stuff that is being sold as weed base ferts wont actually come under the same laws or rules and regulations as lets say normal off the shelf tomato feed. A good example is dodgy PGR`s in certain boosts I'm pretty sure these wouldn`t make it to shelf over the pond in States. What do you recon mate ?

Thanks for your input guys. I've been working on a POC of the tool described. Nothing worth sharing yet, but it has a whole bunch of recipes for different nutrient suppliers and can calculate optimal ratios based on the size and stage of the plants and will adjust for VPD. You plug in the light size, power, target DLI and your room stats like temperature, humidity, leaf temperature etc and it spits out the correct amount of each component to add to a reservoir as v/v and w/v.

It can only guess as you'd need to create a constant feedback loop of some sort to achieve that, but it will get you in the ballpark range. Also displays each element as elemental PPM, so a grower can say with confidence that they don't have X deficiency.

Seems a good idea especially for helping newer growers out.

I have quite a bit of insight to the goings on as I worked within the hydro industry for many years.

Back in the day, there was the usual suspects like Canna, Growth Technology, HESI, Atami yada yada. They were always top-notch and adhered to standards. Then the industry blew up and it all got a little distorted.

I met the guy that creates Hydrotops when he was working from his house and mixing it up in his bath He was actually a good guy and what he was selling was in fact decent, but many of the other cowboys wasn't.

The UK has some of the most strict laws in the world. Another friend of mine has just bought distribution rights into the UK for a well known brand. I promise its not me and my work on this calculator is totally unrelated unless he pays me a shit load of money. The shit he and the manufacturer has to go through to get it shipped over is crazy. They want to know EVERYTHING and some.

That being said, I'm told there's quite a large quantity of fake products that end up in circulation. You have these smaller companies that exist below the larger companies like Hydrogarden and Growth Technology that sells all the dodgy shit like the fake Dr Shimols spidermite spray and the PGRs that you wouldn't want to be consuming. They also offer more reputable brands at a discount price. I'd have a guess that it's probably fake too.

The government do in fact activey shut these guys down. But they just string back up under a different name and continue as they were.

The laws across most of the world around guarenteed analysis is that the company has to meet the percentage displayed as a minimum. Quite often they will over compensate to ensure they don't go below those figures and end up in hot water, so quite often add more. The more sophisticated and accurate the equipment used, the closest the figures are.

I've also been researching electrochemical neutrality and how a cation/anion imbalance can cause more fluctuations in PH. Some companies do a better job of this than others too. Some I've crunched the numbers for have a 40% imbalance!

[2-Scoops]

Back in the day, there was the usual suspects like Canna, Growth Technology, HESI, Atami yada yada. They were always top-notch and adhered to standards. Then the industry blew up and it all got a little distorted.

When i first went in a grow shop man it was just a stall down in the local market and all that was on sale was Gro-Tec, Vitalink and pk booster. Students had set it up, man its its one of biggest grow shops in UK now and nation wide. Good fun back then.

So how long to create the app man ?

[seymore_budz]

Back in the day, there was the usual suspects like Canna, Growth Technology, HESI, Atami yada yada. They were always top-notch and adhered to standards. Then the industry blew up and it all got a little distorted.

When i first went in a grow shop man it was just a stall down in the local market and all that was on sale was Gro-Tec, Vitalink and pk booster. Students had set it up, man its its one of biggest grow shops in UK now and nation wide. Good fun back then.

So how long to create the app man ?

Depends on other commitments really. The plan would be to trial it myself for a while, then roll it out to some people to test out and gather some feedback. Currently, I'm just using Google sheets and creating custom functions, but it's not hard to pop all that into an app. Most of it is simple java script and standard maths. Most exotic thing is the linear regression predictions, but those are a piece of cake using a third-party library. I'd probably use the spreadsheet right up until I have some feedback.

Most of the guys with growshops started like that. It's awesome to have seen the industry grow as a whole. Completely different landscape now.

[2-Scoops]

Depends on other commitments really. The plan would be to trial it myself for a while, then roll it out to some people to test out and gather some feedback

I mean im not into too much faffing with this n that n other, but if ya get that far I'm willing to jump in and give ya feed back if it helps out and its simple enough. Nowt down for over complicated techi stuff. Anyhow just shout if needs be and you get that far mate. .