# What Causes My PH To Rise?



## KrispyKreme (Jan 28, 2007)

I have a 28 gallon tank running for about a year. My PH is 8.0 sometimes 8.2 (my test kit is not calibrated). Just for fun I tested the water right out of the tap and the PH is 7.4. Why is the PH higher in the tank than from the tap?

Substrate – Flourite (Seachem’s web site says it doesn’t affect PH)
Water changes – Weekly about 30%
Big piece of Malaysian driftwood (which I thought, if anything, would lower the PH)
KH is 15 in the tank and 18 from the tap
Various crypts and anubias are in the tank
DIY co2
Few White Cloud Mountain Minnows and Harlequin Rasboras

Any ideas or suggestions? Need any other water tests?

Thanks
Matt


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## hoppycalif (Apr 7, 2005)

Assuming your KH is 18 ppm and not 18 dKH from the tap, your tap water contains some CO2, but not much in the tank water, so the pH goes up. That is low KH, so it doesn't take much difference in CO2 to change the pH that much. This is just a guess. DIY CO2 can lead to very little in the tank water if you have any leaks at all in the CO2 system.


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## ValorG (Dec 23, 2007)

Are you adding anything to the tank that you may of forgot to mention? Any white rocks in the tank?


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## KrispyKreme (Jan 28, 2007)

I feel like an idiot, I was hoping this thread would die and I wouldn’t have to admit how dumb I am. I haven’t been paying much attention to co2, ferts, water parameters for months. I forgot about the whole kh, co2, ph thing. Now that I have my DIY co2 working correctly the ph is in the 7.2 – 7.4 range.

Thanks for helping!
Matt


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