Re: Aquatic Plants Digest V2 #93

> Aquatic Plants Digest       Thursday, 23 May 1996       Volume 02 : Number 093

> > From: Sharon Stewart
> > Subject: CO2 woes

> Snip...

> > Before the co2 was  added the tank water ph was swinging out of control (7 to 8 one day 8 to 9 the
> > next) and KH was dropping to 2.  I have the controller set to turn on the co2 at
> > 7.3  w/ a bubble a second.  It works great for a day or so and then the ph
> > starts climbing to 7.6 and above.  I keep swearing at the reactor, but maybe
> > that isn't the culprit?  The Sandpoint reactor has been very difficult for me to
> > regulate. When I first got it, it was next to impossible for me to find a
> > balance between enough water flow going through the reactor and blowing the co2
> > out of the reactor.  I'm using an Aquaclear 802 powerhead (the 301 wasn't
> > powerful enough).
> >    This is driving me crazy, every day I'm fiddling with the co2.  Should I just
> > not worry about the rise? Or is my reactor just not very efficient? If it is my
> > reactor, can anyone suggest a better one?

    I also have a Sandpoint CO2 system. Mine has an electric solenoid hooked to a timer 
so that it is on whenever the lights are on. I have had no trouble whatsoever. My water 
hardness is similar to yours. (about 3 KH) My ph is very stable at 6.8 . I check my 
hardness and ph weekly. Although, you have an automated system, our reactors should be 
very similar. I'm curious as to why you thought that you needed a more powerful 
powerhead. My reactor is an ugly green monster with suction cups that hold it to the 
tank. It has a valve that allows you to regulate the amount of water flowing into the 
reactor. When set properly, a venturi effect is created. In other words, the CO2 bubbles 
are swirled violently at the top of the reactor, as water is circulated from the top 
downward and eventually out the bottom. Although there are fins scattered down the 
length of the reactor tube, they don't seem to trap very many bubbles. This leads me to 
believe that most of the CO2 is being dissolved at the top of the reactor where most of 
the mixing is taking place. 
    It seems strange to me that it works fine for a day. One would think that the 
reactor either works or it does not. Are there possibly other factors at work here?
How reliable is your controller? How about your needle valve? How about the pressure in 
your CO2 tank? What type of substrate do you have? And if your ph was bouncing from 8.0 
to 9.0, wasn't this wreaking havoc with your fish as well as making your plant growth 
wildly erratic?
                                                              Pat Bowerman