When vegging is it best to use a 20-20-20 mix in nutrient free potting mix and then during flowering to use ethier a 10-52-10 or a 15-30-15 mix and then stop feeding in week 5 of flowering
good question, I wondered this myself. You also have those 'natural fertilizers' such as bat crap and worm castings to consider ... you also have the brand name fertilizers/growth boosters that one sees all over hydro stores to consider as well. Answers to which to use and not use would be a good thread to have here...I'm sure many ppl have the same question.
It's a bad idea. The same way growing in a smokey room (be it cigarettes ot pot smoke) will have lesser yeilds and poorer quality bud, the same will happen if you use water that isn't at the very least pure (the only thing betterthan pure water is water with the right balance of nutes). Except for the fertilizer, don't give your plant any water that you wouldn't drink.
A marijuana plant is fragile. If you polute it, you're gonna kill it, for sure.