Discussion - Do you dose by volume or weight?

[seymore_budz]

Many growers I know dose using volume. So if they have 1 litre of water, they would add Xml of solute to their solution. Trouble is this isn't the most accurate way to measure solute. When making 1ltr of solution, small errors can make big differences to the overall composition of the solution. The other way to do things is to weigh the solute rather than judge by eye. The downside is it takes longer, requires you to setup scales and maybe overkill as we'renjust growing weed ffs :)

How do you do things? You a pipette type of person? Or do you like to bust out the scales?

[JJ]

I use 1 gal. jug,,,add 1--5 ml. grow or bloom ..depending on time
+microbes
+cal mag now n then
+fish stuff
I have great well water ph.
So I do volume...weight imo would be dry nutes

[Grumpy Toad]

Pipette for me. I added white paint marks to help with dark liquids

[seymore_budz]

I use 1 gal. jug,,,add 1--5 ml. grow or bloom ..depending on time
+microbes
+cal mag now n then
+fish stuff
I have great well water ph.
So I do volume...weight imo would be dry nutes

Weight can be both. Quite often I knock up smaller batches for small plants. If I prepare 1ltr of solution then the amount of solute required are quite small.

Let's say I mix up 10ltr of solution. My recipe calls for 20ml of A and 20ml of B. I measure out 20ml of each, but overshoot by 0.3ml. That's just a 0.15% difference. The next day I need to an additional 1ltr to water some smaller plants. I do the same and add 2ml of A and B, but overshoot by the same 0.3ml. Now we're 15% over what was required. 15% may be enough to cause issues if compound over sever weeks to a month.

Pipette for me. I added white paint marks to help with dark liquids

Excellent idea! I really struggle to see those markings too. My flask has orange markings. Can't see them at all if the fluid is dark.

[2-Scoops]

I use the Canna A&B 1 litre bottles that have a measuring doo-dah on bottle in mls, it just makes everything really simple, ok maybe not most accurate measuring tool but they seem to do jobby good enough, when the bottles are empty i just refill them out of my 5 litre fert bottles with whatever ferts im using at the time. But if I'm adding other stuff like silicon or a boost i will use a syringe or a small measuring pot to pour it into before adding into my tank.

[Marcus]

Volume for liquids, weight for dry stuffs.

Unless you know the density of the liquid and can apply a conversion factor?

[seymore_budz]

Volume for liquids, weight for dry stuffs.

Unless you know the density of the liquid and can apply a conversion factor?

Yup, good point. 1ml != 1g. A lot of bottles supply the net weight that can be used to convert v->w or you can weigh a specific volume to establish the density.