# Too much oxygen?



## kookus (Apr 23, 2010)

Hello

Was wondering if too much oxygen drives PH up? or does it drive it down?

The tank right now has only a FRT and its at a ph of 8. 220 gallon tank with a 90g sump. Its been running for about a month now. 2 air disks?

Thanks


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## plantedinvertz (Apr 21, 2010)

Carbon dioxide makes it go down.. Oxygen makes PH go up.


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## neven (May 15, 2010)

i thought it was CO2 drives the PH down, but o2 drives out the co2, so it indirectly raises the PH through that. But if you have no injected co2, the ph difference would be next to nothing.


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## Fish Whisper (Apr 22, 2010)

that's great news, this might be a step in solving my pH problem


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## eternity302 (Apr 22, 2010)

I always though O2 drives CO2 out, like Neven said, but it doesn't drive the PH up! I always thought that with the O2 being high, it will only stabilize the PH! But I definitely could be wrong, as I'm only assuming!

Maybe test the PH in the water after water change, and test the PH from the tap as well during the water change! Compare it few days later, that'll be a good test to find out!

I'd try that if my tanks weren't planted! =)


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## AvianAquatics (Apr 29, 2010)

eternity302 said:


> I always though O2 drives CO2 out, like Neven said, but it doesn't drive the PH up! I always thought that with the O2 being high, it will only stabilize the PH! But I definitely could be wrong, as I'm only assuming!
> 
> Maybe test the PH in the water after water change, and test the PH from the tap as well during the water change! Compare it few days later, that'll be a good test to find out!
> 
> I'd try that if my tanks weren't planted! =)


I guess if O2 drives CO2 out then it'd make sense that PH will incease. I think it's the carbon that decreases PH. I guess I should've paid more attention to science class lol.


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## eternity302 (Apr 22, 2010)

But drive it up that much? WOW!

+2 for sleeping during science class! LOL!


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## davefrombc (Apr 21, 2010)

Oxygen has no effect on pH. It is almost impossible to have too much oxygen in your tank, and shouldn't drive out CO2.. Agitation of the water surface will oxygenate the water , and at the same time reduce CO2 levels ; not because O2 drives CO2 out , but because the agitation of the water surface causes increased CO2 loss to the atmosphere. If you are maintaining a planted tank and especially if using CO2 addition, you want to use cannister filters rather than HOBs . The cannister filter return water enters below the tank water surface to keep CO2 losses to a minimum while HOB filters would cause greater CO2 loss because of the splashing of the surface with the return water .
CO2 reduces pH because when dissolved in water, it produces a weak acid (carbonic acid)

Here is an intersting article on water chemistry and properties for various industries.
http://www.h2ou.com/h2wtrqual.htm


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## plantedinvertz (Apr 21, 2010)

oops you guys are right about the oxygen thing. lol


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## pistolpete (May 2, 2010)

if your PH is high, you probably have some calcium based rocks or substrate in your tank. It may also be that your test kit is not that accurate. check to see it there is crushed coral mixed in with your grave.

Like the others have said, O2 has a negligible effect on PH, you'd need scientific equipment to tell a difference. Surface agitation and temperature are the two main factors in the 02 content in water.


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## kookus (Apr 23, 2010)

Thanks for all the help. Very interesting about the o2 levels. I'm glad I cant over oxygenate the water.

I'm not using any filter media, just floss. im going to do another big water change and go from there.


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## neven (May 15, 2010)

floss is a decent filter media


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## Rastapus (Apr 21, 2010)

Correct on the O2 issue. You can only reach the same O2 levels of the atmosphere. you can aerate till the cows come home and you wont get any higher then the surrounding air. Sounds like you have coral in there for sure. FRT thrive in harder water, check your hardness, pH is second in my opinion.


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## Fish Whisper (Apr 22, 2010)

Would activated Carbon lower pH?


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## TCR (Jul 13, 2010)

I have 2 tanks

one is 8ph and the other has florabase and drift wood and is 7.8ph. Im gonna try to get hold of some peat and try that in my water changes to see if I can slowly lower it that way. With constant ph checks I think I'll be able to find out if there are buffers in the tank and try to narrow it down after that.


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