stringdemon
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Volumetric Nutrient Conversion
by: stringdemon
This conversion method is intended for those of you who don’t want to make an entire gallon of nutrient solution. It is intended for those of you who see the benefit of preparing fresh nutrients, in fresh water, every time. This method isn't entirely unnecessary, if your a critical grower who enjoys the science aspect of growing... this is for you. The only time that you would really need this is during the early stages of the plants development. Juvenile plants being grown in small containers like "party" cups, don’t require near as much water and could possibly be watered with as little as 300 to 500 ml. For instance, you might know that you are only going to use 500 ml. on your plant and instead of making a full gallon, you decide to only make the amount you are going to use. Unfortunately, the manufacturers only gives you amounts per gallon. by: stringdemon
Here’s a method to calculate proper amounts of nutrients for smaller volumes of water (<1 gal.) (Please note that during the early stages of a plants life, if your growing in soil/soilless mix, they don’t require nutrients, just water. Although if the plants are big enough you could use half strength to a full strength solution, depending.)
1. Write down the feeding schedule. (In this example we'll use General Organics feeding schedule, amounts are per 1 gal. of water.)
- BioThrive – 10 ml.
- Ca/Mg – 5 ml.
- BioRoot – 10 ml.
- BioWeed – 2.5 ml.
2. Take into account that 1 U.S. Gal. = 3,785 ml. or 1 U.K. Gal. = 4,546 ml.
(These examples are in U.S. Gallon)
3. Figure out the volume of solution you will need… in this case we’ll say 500 ml.
4. Now ask yourself the question, (What % is 500 of 3,785?)
500 / 3,785 = 0.1321 (rounded) 13%
5. Your new volume of water is 13% of a gallon and will require 13% of the original nutrient amounts.
- BioThrive – 10 ml. (10(0.13) = 1.3 ml.)
- Ca/Mg – 5 ml. (5(0.13) = 0.65 ml.)
- BioRoot – 10 ml. (10(0.13) = 1.3 ml.)
- BioWeed – 2.5 ml. (2.5(0.13) = 0.325 ml.)
6. Now comes the tricky part… After calculating the new nutrient amounts, we are left with confusing fractions that can’t exactly be measured in equal amounts. If your eye dropper had 10 drops per 1 ml. You would be able to add these amounts to your solution accurately. The reality is that not all eye droppers are created equally and the only way to know is to fill the dropper up with water and then expel the water and count each individual drop in 1 ml. of water. Once you know your droppers range you can calculate the amount of 1 drop in milliliters.
In this example we’ll say there are 20 drops per 1 ml.
7. Divide 1 ml. by the number of drops in 1 ml. or “x”, to figure the amount of 1 drop “y”.
x = (Number of drops in 1 ml.)
y = (milliliters in 1 drop)
1 / x = y
1 / 20 = 0.05
y = 0.05 ml.
1 drop = 0.05 ml.
8. We have now converted 1 drop into a milliliter amount that can work with the fractions of a milliliter. You can now calculate exactly the right amount of nutrients to add to any volume of liquid less than 1 gal.
9. Now take the new nutrient amounts and divide the fraction amount by “y”
- BioThrive – 1.3 ml. (0.3 / 0.05 = 6) Total = (1 ml. & 6 drops)
- Ca/Mg – 0.65 ml. (0.65 / 0.05 = 13) Total = (13 drops)
- BioRoot – 1.3 ml. (0.3 / 0.05 = 6) Total = (1 ml. & 6 drops)
- BioWeed – 0.325 ml. (0.325 / 0.05 = 6.5) Total = (6.5 drops) rounded (6 drops)
Note: Since we can’t produce a half a drop, we would either round up or round down. In this example we’ll round down and say 6 drops. It’s smarter to use less than more to prevent plant burn.
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