I am having trouble with PH fluctuations.

[NolaReefer17]

I Started dosing Kalk+2 about a week ago into my 160 gallon system due to low and unstable ph. I dose 25 ml every hour from 10 am to 7 pm then 60 ml from 8 pm to 9 am. My PH still tanks from 10 pm to about 10 am. Im not trying to chase a specific number, prefer closer to 8.3 but really just want be stable above 8. I open the windows regularly and have plenty of aeration. And a refugium that runs at night. Also the system is close to a year old and alk sits between 9 and 9.5.

 

[rishma]

A 0.2-0.3 pH swing is not unusual. I found that very high volumes of aeration with outdoor air was effective at both raising and stabilizing pH. My swing is now about 0.1 day/night.

 

[Dragen Fiend]

Your going to get swings. I know you want above 8. But if your corals are happy. Don't chase it. Dosing kalk to maintain PH is not the move. And you end up with other parameters going out of whack.

Mine with a refugium and just dosing AFR. I bounce between 7.85-8.1
My corals are happy so not going to chase it. Kalk usually kept be around 7.95-8.2 but I like AFR more for simplicity.

 

[Randy Holmes-Farley Verified Community Expert]

The amount of kalk you are dosing is also too small to help noticeably with pH. Since alk is fine, there’s not much you can do with dosing.