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

Re: CO2 and low light

So...let me see if I have this straight.  In a tank with no added CO2
there is approx. 2ppm CO2, give or take a bit, right?  Let's assume the
tank is moderately planted (50-75%) with typical low light plants such
as Java fern, Java moss, Bolbitis, Anubias, and Crypts at 1.5 W/gal
lighting.  In this scenario would the plants really only consume 2ppm
CO2 or less during photosynthesis?  If so, then I appreciate your
point.  But...let's say you are correct and they only need 1.5ppm. 
Wouldn't it be harder to "find" that 1.5ppm when there is only 2ppm
available, as opposed to say, 10ppm?  Afterall, in a high light tank we
certainly are injecting much more CO2 than the plants actually need. 
Anyone with data or experience?  If this non-scientific point of view is
way off, please set me straight.

Also, the tap water pH in this area runs about 8.0 to 8.4.  CO2 would be
a nice way to bring it down some, and the expense isn't really an issue
here.  So far It doesn't sound like anything "bad" will happen, or for
that matter, anything "good".  Lowering the pH to slightly acidic would
at least provide nitrogen as ammonium, as preferred by plants, correct?

Thank you for your feedback!


> Mike wrote:
> > Greetings,
> >
> > Quick question.  Is there any reason NOT to add CO2 to a low light (1.5
> > w/gal) tank?
> >
> > Mike
> I believe it has to do with the compensation point. That is, the light
> level at which the amounts of CO2 consumed in photosynthesis and produced
> by respiration balance out. Below that point the plant will produce more CO2
> than consume, so there is no point in adding extra CO2. Of course, this
> compensation would be extremely variable from species to species, and perhaps
> would depend on other environmental conditions as well.
> - -Ivo Busko
>  Baltimore, MD