CO2 advice

[slakker]

a pH of 7 is neutral so the Calc Reactor wouldn't work well if the pH is above 7. The water may not be acidic enough to dissolve the media. Have you tested the Ca in your water over time to see if the Ca is being replenished by the Reactor or is it being replenished by water changes? I run my reactor at 6.5 to 7.0 pH and maintain Ca at around 450 ppm.

I have been running my tank at around 7.9-8.3 for over a year and though not optimal, it's been pretty good. The drop in pH at night in normal and one option to negate that is to run a reverse light cycle refugium with some form of algae/plant to take up the CO2 and release O2 into the water at night.

[wil0311]

I used to have ph at around 7.8 to 8.0 because of my calcium reactor but now after adding cheato to my 20 gallon sump and keeping the lights on 24 hours a day, my ph now varies between 8.1 at night and 8.3 daytime. I can see the change on my ph meter within an hour of turning the lights on. I have cheato about the size of 2 basketballs in the sump and it really worked well for me.

[martym]

Tom- There isn't that much of a swing when the lights go off. Drops down to around 7.8 by 5am.
Chin- I have been thinking about a Kalk RX and a Auto top off. Just thought that the 2 combined would be over kill. I like the Cal rx due to it's simplicity.
Tang Daddy- I have a PM cal rx. There is one line going into the tank. The rx is set to the tank Ph. When the MD Ph drops below 8 the Rx turns off, but when the MD Ph goes above 8.01, then the rx comes back on. the effluent out of the rx is 6.7 when it is on. I have the drip into thank around 1.5 drops per second.

So it sounds like I shouldn't worry about it then. Thanks everyone for your help.