pH Controller

[Poustic]

Anyone had good or bad experiences using a pH controller to control your CO2 input in a planted tank?  Any recommendation as to which one would be a good choice, or where to get one at a good price?   Or perhaps you have one for sale?!

[dpatte]

If you are pumping CO2 into your tank 24/7, then your ph may dip down deeply each night when it is dark, as the plants are unable to consume the CO2.

Once simple way i use to keep the pH more stable is to have an extra filter on a timer. When the lights go off in the evening, this extra filter comes on that helps breaks the water surface and allow more CO2 to escape. This will help prevent the ph from crashing overnight (when the CO2 is not being consumed by the plants)

[Poustic]

That's pretty much what I am doing now, with an air pump on a timer for the night, and it seems to help.

But I got a big pH swing the other day when I added a bunch of new plants and forgot to crank up the CO2, and the new plants started needing more of it.   I am also concerned about the "end of tank dump" that CO2 tanks apparently do when they are almost empty.  Not to mention that my needle valve is very hard to adjust - I would need one that allows finer adjustment.  What type of needle valve are you using?

[dpatte]

I am using a homebrew system that funnels the CO2 into my filter intake. I use two CO2 bottles and alternate restarting them each 3 weeks.