Grow Mediums Need a way to circulate water in autopot res that does not change pH

[rz2p]

Why do you think a water pump raises pH? Change in pH requires change in the salts/ions/EC/ppm of the fluid. How does simply mixing water raise (or lower) its pH? Theoretically, mixing water, if anything, should lower its pH, from dissolved CO2 forming carbonic acid; while mixing also raises water temperature.

More likely if you are seeing shifts it pH, it is from microbial metabolism and/or feed nutrients chemically reacting or breaking-down.

A bit old but the pump running 24/7 will warm up the water causing the pH to fluctuate from the temperature increase

 

[Olderfart]

I just stir with a stick when I check the plants usually a couple times a day if I am home. As far as I know, I have not had a reservoir problem with pH. I've been using MCII lately, and a 3 part liquid earlier, neither was a problem.

 

[MIAutomatic]

A bit old but the pump running 24/7 will warm up the water causing the pH to fluctuate from the temperature increase

I do not believe this is a valid concern. If you are just using a standard aquarium pump for aeration then it should not heat the water at all, they are very gentle and low powered, and putting air into water is literally what they are designed to do.

I have switched back to simple soil since I have been growing autos, but I have done DWC and drip hydro in the past. I thought it was generally known that air stones will raise the PH of your nutrient solution. I came across that information from multiple places as I was learning about hydro, and in my grows I noticed that over the course of half a day or so the nutrient solution would go up by about 1 whole point. I will not attempt to explain this with some silly bro science, because I don’t know why it works that way, it just does. As previously stated I am under the impression that this is just basic know information you should have if you are growing hydro.

The solution is very simple, in my system a new batch of nutrient solution always went up one point after 6-12 hours with the air stones. My solution was to just PH the solution one point lower than I wanted it to be ( if your target is 5.8, ph it to around 4.8). Your system might not behave the exact same way as mine did, but just play around with it.

The PH will not rise indefinitely, it’s usually a pretty fixed amount. Just figure out what that is for your system and adjust accordingly.

happy growing!