Large pH swings

[DeletedAccount]

I have never had much of a problem with pH swings.... but, it is my turn now. I have a tank that appears to be doing perfectly - other than that it swings from a nighttime 7.78 to a daytime 8.4 pH.

Normally I keep the tank and the sump on reverse cycles, but this tank has no sump and no place for one. So that won't work.

What other things help stabilize the pH? Is it alk? I don't remember....

[GaryP]

I would check the alkalinity to make sure it is where it needs to be. If the Alk. is low, slowly bring it up and re-test. If it is OK, I would suggest a slow drip of Kalk at night to help even out the pH swings.

[DeletedAccount]

Cool.... very simple!

[GaryP]

Remember that buffering (alkalinity) resists changes in pH. The less buffering, the more of a change in pH can occur.

[Thunderkat]

Did your indoor ventilation change? I read that even the CO2 we exhale can affect pH in our tanks.

[GaryP]

Hino,

I know that at least one of our members has said that he ran his skimmer airline outside and it helped the swings in his alkalinity tremendously. I'm going to try and do that this weekend on my 125.

You would expect the CO2 level in your house to be higher inside then out, unless you lived next to a freeway or something.