Todd March wrote:
>Someone also recommended some "bell" (?) reactor made by Tetra?
I cannot speak for or against the Tetra bells, but I found the following:
In Bernd Greger's "Aquarium Pflanzen", Kosmos, 1991, I found an
alternative to bubbleing CO2 into a filter. It is similar to the
Tetra diffusion bells but cheaper and more flexible. And you can
DIY. BUT it doesn't give values for soft water.
Greger uses a 3 cm (1 inch would do too) high inverted U-shaped channel
into which the CO2 is bubbled. The channel is made out of glas or
plexiglas strips, siliconed together, plus two end caps. The whole
thing can be attached anywhere in the tank.
The dimensions are calculated as follows:
KH Value Contact area (cm2) Channel dimensions (example)
10 dKH 30 cm2 10x3 cmxcm
11 50 18x3
12 70 25x3
13 90 30x3
14 110 40x3
15 130 45x3
plus 20cm2 for each additional 1 degree increase in kH.
These values apply to 100 l (30 USgal) tanks. For a 300l tank,
multiply by 3.
Although, most of you don't have near the 10 degrees kH, I decided
to reproduce the whole table anyways for completeness sake.
Unfortunately, he doesn't give values (or a formula) for our low KH
tanks and since I don't use this myself, I leave it up to you
to figure out how much contact area you need.
I guess that by adding some sort of sliding divider into a 20cm x 1cm
channel, one could fiddle with the contact area until the pH is at the
Three additional notes:
1) By bubbleing the CO2 below the channel into the water, you can then
easily monitor the output of your yeast system. (natural bubble counter)
2) The channel needs to be "burped" periodically to vent other gases that
accumulate over time.
3) This could be a nice set up for a no filter tank.