CO2 advice

[martym]

Yes it is. about 4" I would say.

[Tom R]

Hi Marty

What is your PH after your lights have been on for 4 hours or more.

My Ph falls to between 7.89 and 7.92 during the night and then climes to between 8.2 and 8.3 during the lighting cycle. This is not a swing that should cause any problems.

Some people try to compensate for this by running the lights on their sump on a reverse cycle.

I am running the PH in my CA reactor at between 6.5 and 6.6. I then run the reactor effluent through a second CA stage with no CO2 added. This helps raise the PH before the effluent returns to the system. It is only a partial fix.

Tom

[Chin_Lee]

Marty
MOST reef aquarists have difficulty keeping their pH in the 8-8.3 range due to a variety of factors. Your cal rx is one factor but i don't think its the primary factor. The breakdown of organics in your system is another factors and so is the photosynthesis cycle that occurs during day/night time cycle. Your ph is quite normal for reef systems. You can add 8.3 kH buffers to your system but that will change your alk levels. I recommend using kalk in all your top off water via a kalk reactor if that can fit in your system. I was able to keep my pH in the 8-8.3 range when using this method. And if you wish to maintain 8 dkh, then adjust your calcium reactor accordingly if your dkh begins to creep up too high.