# PH ...out of control



## peacock (May 22, 2009)

Hello everyone

I need some help here

I have a 10 gallon planted tank
A regular tank with the regular starter kit equipment
Gravel-DIY CO2 system

It is a bit over populated but my fish are healthy and the plants are growing fine.

The trouble is my PH: my tap water is at +/- PH 7.2 but the tank PH anywhere between 7.0 and 6.2

Any feedback will be greatly appreciated

Didier


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## WhiteDevil (May 7, 2009)

got wood in the tank?


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## surpera1 (Feb 18, 2009)

Kh ?


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## peacock (May 22, 2009)

Yes I have a small piece of Mopani wood
and I must buy a KH test...just KH or KH/Gh ?


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## surpera1 (Feb 18, 2009)

KH - carbonate hardness - if it is 2 or 3 or higher you are fine - a 0 or 1 can result in ph crash with c02


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## peacock (May 22, 2009)

Hey Good saturday all

I bought a API KH/GH test kit 

tap water KH 5 -GH 7
tank water KH 4 -GH 9

How to explain that difference

CO2 is on for 4 hours and lights for 3 hours: PH 6.7 and I will check again later tonight

Once again everything is fine in my tank.Just trying to understand the fluctuations in my PH.

Thanks in advance


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## Philosophos (Mar 1, 2009)

Start with calibrating your test kit. DI water is good for pH calibration. KH can be calibrated with some sodium bicarb in DI.

The CO2 is contributing, no doubt about that. Heavy feeding or infrequent water changes will also cause a pH crash, but that's usually associated with the KH bottoming out, too.

Unless you're keeping some hard water fish, 6.7 is nothing to panic over. My tank runs 6.2pH and everything is happy; pencil fish are growing very well, otos hang out near the CO2 diffuser, shrimp are healthy, and the apistos are in spawn with fry.

-Philosophos


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## peacock (May 22, 2009)

Philosophos said:


> Start with calibrating your test kit. DI water is good for pH calibration. KH can be calibrated with some sodium bicarb in DI.


do you mean distilled water when you say DI?

and what do you mean by calibrating?


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## Philosophos (Mar 1, 2009)

DI = distilled/deionized

Calibrating as in testing your test kit for accuracy. Pure DI should be 7pH. Baking soda can be added by weight to DI for a standard KH solution, or you can use some 4dKH drop checker solution to check its accuracy. 

-Philosophos


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## peacock (May 22, 2009)

Thank you Sir


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## Philosophos (Mar 1, 2009)

oops belated double; old browser window.


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