I do not spend the $$ for leaf tissue samples so I don't know the levels of chemicals in my res. My approach is to use three data points - the EC, the trend of the EC, and total amount of add backs (RO water that's used to top off the res).You do full change outs? When i read under current’s instruction manual it says to do 50% change out usually. I dunno which to do cause i am new. Thanks
Generally speaking, once the EC of the res has fallen by about 50% and the amount of add back RO ≈ 50% of the res capcity and if the EC continues to drop, I'll swap the res.
What Current equipment are you using?
"i am new" - same here
I saw that you were checking out a thread about adjusting nutes and one posting stated that the grower had to add CalMag because he's using RO. It may be true that he needs to add RO but that's not true in all cases. RO removes some chemicals that plants want (calcium and magnesium, for example) but that doesn't mean that you have to add calcium and magnesium. Like so many other things, "it depends". I used pretty bottles for a couple of grows but, as my "process maturity" improved, I switched to a dry fertilizer that's designed for RO.
Last edited: