pH problems

[Reefmedic79]

Just did my weekly water test and found that my pH has dropped to 7.8 need a quick way to bring up the pH besides doing a water change as the water I was going to use awas to old and had started growing algae in it so it will probabky be a day or 2 before i can do one. Hpw big of a fluctuation is expected between the lights being on and off. If its possible to be the big of a gap that may be the only problem as I tested last Fri at about 10 PM and the lights had been on all day. The test results showed that it was 8.4. Also what are the expected levels of Phosphate in a reef tank.

[toddpolish]

pH is higher when the lights have been on all day. It's the lowest right before lights go on.

I wouldnt' worry about pH too much. In the first few months I freaked out cause my pH was at 7.8 too. it's not as important as other parameters in this hobby.

[smokie]

Is there a safe way raise PH without doing a water change?

[Reefmedic79]

Thanks todd for the quick response and to anybody else who reads this post I second smokie's question.

[MalHavoc]

What's your alkalinity? The carbonate/bicarbonate equilibrium in sea water acts as a buffer to maintain a stable pH. Low alkalinity can often be the cause of big pH swings over the course of a 24 hour period.

Other things to try include adding a refugium to your sump (if you have a sump) and placing some macro algae in it, and lighting the refugium when your main lights are off. This way, something is always consuming CO2.

You can also try aerating your water to improve gas exchange.

[rmendis]

You can raise pH with limewater, sodium carbonate, Kent Marine Superbuffer, or some other buffering agent. Be careful; you don't want to throw your alkalinity/calcium ratio out of balance.

See these threads for more info:
1) http://archive.reefcentral.com/forums/showthread.php?s=&threadid=269761&highlight=raise+ph
2) http://archive.reefcentral.com/forums/showthread.php?s=&threadid=244443&highlight=raise+ph