are you groing soil or hydro. if i understand right you are mixing nutes and letting them sit for a few days and using it to water your soil/soilless plants. if that is the case this is a big nono. it says right on most fert bottles to use the ferts after you mix with water and discard the leftovers. saving the leftovers for watering a few days later can cause problems that you don't want to deal with.

if you are growing hydro just ignore my rambling.
justaseed Reviewed by justaseed on . How come the Ph will change? I have noticed that when I mix my water and nutes I will test the Ph. and bring it to desired measurement. The next day when I test it again I notice it drops a couple points. I check cal on the Oakton tester Pen and its perfect. I've read on the forums to always check and re-check the Ph again and again. Does the PhUp/Down just disappear and disolve in the water? should I even bother to set the Ph of my water a day ahead of using it,or before i leave it to sit for a few days? I use a One Rating: 5