CO2 Levels, What are they Really !

jrneuzil

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Mar 13, 2005
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I am trying to find out what my CO2 levels are and with the help of others on some other forums I am coming to believe that something in the water may be giving me a false reading. Out of the tap my pH reads at 7.4 with a KH reading of 22 or 392ppm. After being in my tank for two weeks it reads at 16 or 285ppm. These numbers would of course normally indicate pretty high CO2 levels.
I am trying to get a copy of the city water report but have not been able to get that yet. I was wondering if there something specific I should be looking for. Any other suggestions would be welocomed.

JR
 

Tom Barr

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Jan 23, 2005
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Re: CO2 Levels, What are they Really !

The pH/CO2 will change, the KH generally will be stable if you have CO2 and are adding it correctly, algae nor plants will use KH unless the CO2 is too low.

Test the pH of the tap water etc after 24 hours on standing in a glass. The pH will higher.

Tap water is often rich in CO2.

Regards,
Tom Barr
 

jrneuzil

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Mar 13, 2005
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Re: CO2 Levels, What are they Really !

I will do that, but what about the reading of 16 for the KH in the tank. Do you think I should view that as a reliable level and and aim at 30ppm of CO2 with a pH target of 7.2 ?
 

Ian H

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Jan 24, 2005
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Re: CO2 Levels, What are they Really !

jrneuzil said:
I will do that, but what about the reading of 16 for the KH in the tank. Do you think I should view that as a reliable level and and aim at 30ppm of CO2 with a pH target of 7.2 ?
If you determine the Kh is stable then it should be fine. If your tapwater is a higher Kh and on the assumption you do water changes this will raise the Kh of your tankwater and also the Ph.

Just a word of warning, I was testing with a faulty Kh kit at one stage and it completely warped my results.

Ian
 

jrneuzil

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Mar 13, 2005
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Re: CO2 Levels, What are they Really !

On the off hand chance that that had occurred I had ordered the Lamotte Alkalinity test and Carbon
Dioxide test and got the same results.