Re: CO2 thoughts ...

>From: George Booth <booth at hpmtlgb1_lvld.hp.com>
>Date: Thu, 30 Nov 1995 10:54:35 -0700
>Subject: CO2 thoughts ...
>That means the CO2
>concentration goes from 17 ppm overnight to 5.5 ppm in the late
>evening (those plants really suck up the CO2, eh?).  Note in this case
>that when the plants are trying to photosynthesize the most (the late
>afternoon), their source of CO2 is at a minimum.  Bummer.  This is why
>a $$$ controller is good; it can provide all the CO2 the plants need
>by increasing the amount delivered when it is neded.
>[I've never thought about it this way before]

George, have you experimented with growth rates at different CO2 and pH
It is conceivable to me that since 5.5 ppm is >0, then 5.5 ppm may be
sufficient CO2 concentration for plant photosynthesis! So, as far as CO2 is
concerned, pH 6.5 or 7.0 may not matter!

However, some pH may be preferable to other pH because of ability of plants
to absorb nutrients or to limit toxicity to certain chemicals. I seem to
remember discussion about this somewhere (probably in TAG :-). Doesn't Dupla
recommend pH near 7.0? This may be for a reason other than to sell their KH
tablets. :-)

Maybe someone can look this information up and summarize it here for the group.