Magnesium deficiency correction with Epson salt while running autopots and Gaia Green

as long as S isn't high, shouldn't run into any issues using magnesium-sulfate. you'd have to calculate what you feed and then consider how it occurs over time... so this will be a lot of trial and error on your part given your method of growing. You could work backward from what a soilless/hydro provides and figure out grams/week you need to add... my plants are happy around 80-85ppm Mg given every feed (100-110 ppm S). fwiw, i have very hard water and probably get some extra minerals from that too. i'm supplementing what is in my "Part A" base fertilizer with about 1g/gal of epsom salt. my total ppm is 85, but that again is a context of fertilizing every single irrigation with an ondemand concentration level of each molecule. YMWV - "will", not maybe... any foodgrade epsom salt willb e fine.. just make sure nothing added and just pure.. should have a guaranteed analyisis label saying it is 100% magnesium sulfate. e.g. a cheap equate brand from walmart, unscented is fine... don't have to overpay for it.. 6 $ for 8lbs and should last you 2 years or more.