poundpusher2009
Well-Known Member
I have very little knowledge of Hydro. If you were to have a 70 gallon resovoir how often does the water have to be changed?
I agree with Meangreen. I have a 40 gal res that I change weekly.i whould change it every week to 9 days..depending on what nutes you use?...because some nutes just get nasty.....
The reason for changing it regularly is that is the only way to reset the nute concentration. Plants don't always uptake equal proportions of all nutes and you don't know which are getting to be in higher or lower amounts. You can check ppms, but it doesn't tell you ppms of "what."