Reef Central Online Community - View Single Post - How to raise PH without raising alkalinity ?

fingersdlp · 05/30/2007, 02:36 PM

Regarding Co2 issues...

I have a standard 180 gallon tank 6 x 2 x 2 I believe (All Glass). The ph is always fine on it. I also have a 156 gallon 6' x 18" x 30" with a glass center brace taking 1/3 of the top surface area. The ph is a problem and I try to keep the Alk around 4 to help it stay up. I have two pinpoint ph meters and use salifert for the alk test.

I believe the tall tank configuration has poor oxygen/CO2 issues. I have tried to increase surface agitation but it has not helped much.

I think some tank configurations can be a problem to keep the ph in the good range. I see a ph of 7.7 or 7.8 all the time in the morning even with my Alk > 3.5 so I know it is a CO2 problem. I am even considering adding a bubble wand inside the overflow to see if it will help but I am worried the salt creep will be a problem.

If you are using glass covers you may try replacing them with egg crate. I would not have thought that the tank shape would really matter that much but I have no other way to explain the difference in PH between my tanks since they have similar habitat, fish and corals and even use mostly the same equipement. The biggest difference is the amount of surface area exposed to air.

B.

05/30/2007, 02:36 PM	#15
fingersdlp Registered Member Join Date: Jan 2006 Posts: 218	Regarding Co2 issues... I have a standard 180 gallon tank 6 x 2 x 2 I believe (All Glass). The ph is always fine on it. I also have a 156 gallon 6' x 18" x 30" with a glass center brace taking 1/3 of the top surface area. The ph is a problem and I try to keep the Alk around 4 to help it stay up. I have two pinpoint ph meters and use salifert for the alk test. I believe the tall tank configuration has poor oxygen/CO2 issues. I have tried to increase surface agitation but it has not helped much. I think some tank configurations can be a problem to keep the ph in the good range. I see a ph of 7.7 or 7.8 all the time in the morning even with my Alk > 3.5 so I know it is a CO2 problem. I am even considering adding a bubble wand inside the overflow to see if it will help but I am worried the salt creep will be a problem. If you are using glass covers you may try replacing them with egg crate. I would not have thought that the tank shape would really matter that much but I have no other way to explain the difference in PH between my tanks since they have similar habitat, fish and corals and even use mostly the same equipement. The biggest difference is the amount of surface area exposed to air. B.