Exact equivalent GH Bloom DIY
Okay.... I finally got it right!!! I was able to figure out that GH FloraBloom most probably doesn't contain 1.5% Magnesium because the only water soluble source of Magnesium that is suitable for hydroponics is derived from Magnesium Sulfate. You can check that fact on Wikipedias solubility chart. Magnesium Sulfate Heptahydrate (Epsom salt) or just plain old Magnesium Sulfate will always be heavier with Sulfur than Magnesium. A 4:3 ratio approximately. So, when you make a mix containing 1.5% Magnesium (what the GH FloraBloom label states as guaranteed analysis) you will also be guaranteed MUCH more Sulfur than 1% that it claims on the label. Add to this the fact that the label claims "Combined Sulfur" (2 sources of S in this, Epsom and Potassium Sulfate), you will end up pulling your hair out trying to make sense of the label. So, I'm betting that it contains 1.5% Sulfur and 1% Magnesium instead because when I added up my new formulation, my math is checked to be correct because the Phosphate percentage comes out damn near perfect to 2.2% that is actually in there.
Fertilizer laws require the label to state 5% available phosphate, and 4% soluble Potash. In reality, you multiply 5 by.44 to get 2.2% and multiply 4 by.83 to get 3.32%. The Magnesium is 1% and the Sulfur is 1.5%. Here is the formula for a GH FloraBloom alternative.
385.71 grams Epsom Salt
381.12 grams Monopotassium Phosphate (trade name is MKP fertilizer, 0-52-34,actually 0-22.88-28.22 for formulation sake)
35.66 grams Potassium Sulfate
2977.51 mL of warm pure water
Have the water ready in a plastic gallon jug. Add a solid, shake it up. Repeat three times. Make sure it's all dissolved. Dose it the same way you would the GH Bloom. I also know how to make the correct formulation for Flora Micro with chelated trace elements, but you're not getting that until next month. If you're feeling lucky, use my Bloom formula with the store bought GH FloraMicro and you'll see that the Lucas formula will give you the same results when applied to the DIY Bloom/Store bought Micro combo. Hope this helps.
Last edited by problemsolver; 05-17-2012 at 12:56 AM.