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Re: more CO2 regulators

Mark Gilmore wrote:


> It seems to me that a pH controller is a REQUIREMENT for any CO2 system to
> function reasonably.  As long as the water has a reasonably stable kH, a pH
> controller will maintain constant CO2 levels.  Such a system contains
> feedback, and forms a "closed loop" control system.  Closed loop control
> systems essentially compensate for drifts/inaccuracies of any component in
> the system, including the "plant" (the aquarium water in this
> case).  Without a pH controller, the system is "open loop", and one must
> try to adjust the flow rate (splitting hairs) to keep the CO2 (or pH) constant.

I personally use regulation (ie active feedback; sure hope that power doesn't go out!  ;)
and I like it for the reasons you mentioned, especially for giving the fish a stable pH
environment. But I think many on this list will argue that, once you have the CO2
injection rate adjusted, the pH doesn't really vary so much as to require a control
system. If your water really doesn't have much buffering, variations in CO2 level will
have a greater effect on pH, though.

Some people have a non-feedback control system of putting an airstone/pump combination on
a timer, so that they can run it for a period every night.

But still I enjoy my controller, and it does provide a (somewhat expensive) solution for
the CO2 dumping problem.

-- Stephen Boulet