Jacks 321 40 gallon reservoir

Does anyone already have this mixture scaled up to cups? If so save me the math. My GH series nutes will soon run out and i will be running jacks 321 next.

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You should be weighing it.


You’ll have to figure out the weight of Part A and Part B per cup and scale from there.


I had in grams. I need cups

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I think you’d be better off by weighing. You are trying to convert from weight to volume which can only be done by weighing anyway. For 40 gallons:

Part A: 144 grams
Part B: 96 grams
Epsom: 48 grams

Silica you’d do by volume.

Just my thinking on it. I mix 5 gallons at a time and just weigh it out.


I had been just mixing the GH in the reservoir. Ill try the 5 gallon way with the Jacks. Thanks

My silica is liquid based.