[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: CO2 question

> From: RFellows at concentric_net
> Subject: CO2 Question
> I was just curious about the KH/pH/CO2 tables.  My water has a KH reading of
> 71.6 ppm (4 dh) and a pH of 7.4.  According to the chart, in order for me to
> reach optimum CO2 levels I need a pH of 6.9 or 7.0.
> So my question is isn't there a way to lower my pH besides CO2 injection?

	It sounds as if there is a misunderstanding of the KH/pH/CO2
relationship here.  The CO2 concentration in the aquarium water is 
decided by your CO2 system, the atmosphere, and to a lesser extent, 
by the plants and fish in it.  You can use the pH as an _indication_
of CO2 concentration, if you know the KH.  You _cannot_ alter the pH
as a method to change the CO2 concentration.  If you add acid, to cut
the pH, you destroy KH.  There is a temporary increase in the CO2
concentration (made by destroying the HCO3-), but the equilibrium with
the atmosphere, etc. will be re-established at the same level as
before.  You then have the same CO2 as before, a lower pH than before
and a lower KH than before.

> I am having a terrible time with the DIY yeast method and cannot afford a
> real CO2 setup at this time.
	I think that you should be O.K. without a CO2 system.  I have three
taks that run just fine without, and only one that has one. 

Paul Sears        Ottawa, Canada