Simple pH Question in FOWLR

[The_Nexis_One]

A friend of a friend (this person actually does exist) has a 200 Gal FOWLR. He is running a Calcium Reactor (Alk at ~12dkh, Ca ~400) for Coraline Algae, VHO light, average flow, and a CC bottom - Oh, and fish that will no allow for Macro's or Corals in the display. The problem, as he has relayed to me, is that the pH is 8.0 to 8.1 continuously. He has only a few mushrooms on the LR and nothing to photosynthesis the CO2 into oxygen to raise the pH. While I understand that this pH is Not a serious problem. He would feel better with a pH of 8.4 - and therefore, needs your help.

What can be done to help the tank "Gain" pH?

Thanks,
JB

[Grandis]

Hi,
1) pH around 8.0 / 8.1 during the night time would be ok for you. Did he mesure it at night? Maybe during the day it's a bit higher, if so. The micro algae in the tank will make difference.
2)Make sure that the tests for pH and alk are not expired.
3) Does it has coralline algae already? If it's growing there is no reason to worry.
4)You can try to put some buffer.
Grandis. :)

[The_Nexis_One]

As I've been told. The pH was tested several times over several weeks... at night it's 8.0 during the day it's 8.1... The Ca reactor is keeping the Alk (buffer) around 12 - which is actually high...

I believe the the LFS seconded some of the tests so, I'm not doubting the test kits.

there are no macro's or corals - but there is Coraline algae on the LR...

what is the normal pH in a FO/FOWLR tank? Could this be a case where their is nothing substantial in the tank to "raise" the pH above 8.1? if this is the case and the tank just doesn't "fluctuate" - what could be done to raise the pH once to get it into the right range and then maintain it with the Ca reactor?
Maybe my thinking is completely off base here - but with my limited experiance with pH, that's where I'm at.

Thanks for the info.

JB

[Grandis]

Hi,
The pH for a FO tank can be maintened about 8.2. About 8.0 at night is fine. The coralline algae will do ok with this pH. I don't think you should worry about that. Are they growing (algae)? If so, don't worry. If the alcalinity is too high, sometimes the pH has a negative reaction (drop the number). Try not to add buffer for a while to drop alcalinity. If possible do some water changes with a good salt (like Instant Ocean) to help the process. Tell him to relax man. It's just algae. Make sure he doesn't hurt the fish when palying in his system and because he's worried about the water chemistry. Some fishes are sensitive to it. Go slow.
:)
Grandis.

[billsreef]

Before going to crazy, have him perform a simple test for C02 retention. Take a sample of water, test the pH then aerate the sample heavily for about 20 minutes and retest. If the pH has gone up in the second test then the system is retaining CO2 and simply will need better circulation and gas exchange. Base on the alk and Ca values this quite likely to be whats happening.