Nightly Shutoff or PH Controller?

I used to use a controller and it can keep things like an end of tank dump from killing all of your fish, but in the end thought it was a bit excessive. I don't look for particular ph levels to determine if I have reached certain CO2 levels. I wouldn't try to use it against the ph/kh/CO2 chart.

They work and you can use them but they aren't needed. So it really comes down to personal pref. I prefer solenoids and timers. You should use a DC no matter which way you go.

If you have high light, and are using the optimum bubble rate on the CO2, you should shut it off at night. Otherwise the concentration may be greater at night than during lights on, and that could be very hard on the fish. But, if you use a much lower bubble rate, like for a low medium light tank, it doesn't harm anything to leave it running 24 hours a day. A pH controller may let you keep a high bubble rate at night, but I wouldn't want to trust it for that.

OK, thanks for the information. I appreciate your responses, and will keep your recommendations in mind.

FWIW...I have a pH controller on a timer that comes on 1 hour before lights come on and turns off 1 hour before lights turn off. I have been doing this since January and it does a great job for me. I check my probe once a month and the most it has ever been off is .1.

FWIW I prefer a solenoid on a timer. I don't see it worth the risk to run 24/7 since I don't do massive amounts of O2 aeration. I would use a drop checker either way you go. I use the DC as a point of reference tool and not so much the end all, be all. Algae has a way of letting you know you're not providing a balance in a tank.

Gparr, thanks for the reply. I have been strongly considering a PH checker if I decide to go with the CO2.

Thanks to all for your responses.... Phil