Originally Posted by
tank a holic
http:///forum/post/3208397
I saw this come up in another thread but I didn't want to hijack, so....
if dkh and calcium are on target, and ph is low is it safe to assume you have excess co2?
and if you have good flow, in what other way can you lower it?
Depends on what you mean by low pH. PH like 8.2 or so can be more or less normal but if pH is down under 8 then IMHO it does signal potential problems. But even with that we had a local here who had been growing sps corals for years, selling frags and so on. His pH was 7.5 or so.
IMHO low pH always signifies high co2. The more serious question is how did it get there. In the example above the local dialed back the calcium reactor co2 and ph rose. Dripping kalk rasies pH.
But for a more normal, non calcium reactor, non kalk setup, The single best way to get pH up is by adding macro algaes. To me that simply trumps anything else. Especially, if the tank also had nitrates and phosphates. The macros raise pH by making the tank a net consumer of carbon dioxide and producer of oxygen every 24 hours. Plus they will also consume nitrates and phosphates.
My 55g had a pH of 7.6 or lower until I added macro algaes. In a week pH was above 8.4 (api test kit) and has stayed there for years.
also be sure to measure pH just before lights out and if high don't worry. That last thing you want to do is start making drastic changes for a low just before lights on pH value.
my .02