[JanS]

Part of it depends on your water too. I had one on the same timer as my lights and with my high KH I realized the pH was really rising over night when the C02 turned off with the lights. Now I have it on a controller and it runs nearly 24 hours and keeps the pH much more consistent.

 

[JanS]

I thought i would just add. Out of curiosity, with the unit on or off at night, how much of a ph fluctuation do you guys see. Im not currently using a co2 setup, i have in the past but scrapped it. Is it a full 1.0, or are we talking 10ths of a ph here? Just your own findings, thanks.

In my case, it stayed around 7.0 during the day, and just before the lights and C02 came back on it had risen to around 8.0. :shock: That's with a KH of around 9. Now with the controller, it hangs at 7.0 and I'm sure my poor fish appreciate it much more. Maybe my Hongsloi's will reward me with a spawning now.... :wink: