Co2

[noah]

I was just wondering if anyone pays attention to Co2 levels in there tank. I have heard that somtimes at night without photosynthesis from algaes and other plants taking place the Co2 can raise and somewhat suffocate your corals. somtimes i think this may be happening in mine because in the morning some of the corals espescially my elegance are some what closed up and look stressed. Is this just them adjusting to the light and dark periods or could there be lack of oxygen.

[Doug1]

CO2 buildup from plant and animal respiration causes the pH to drop over night. The two ways to combat this are to run a skimmer and or sump to increase oxygenation of the water and outgas the CO2 and kalkwasser drip at night to replace evaporation. The kalk hi pH (around 12) will keep the pH up and bind CO2 as well as phosphates

[tdwyatt]

Corals: normal diurnal rxn

CO2 normal as photoshythesis stops with end of photoperiod and chlorophylled critters turn to normal respirations for carbon. Good surface circulation or reverse photoperiod refugium with macroalgae will slow this daily swing if it bothers you, but it is pretty much normal and not stressful to the tank biome.