Re: CO2 reactors

 > From: trigg at jane_cs.waikato.ac.nz
> Date: Mon, 1 May 95 14:20:46
> Subject: CO2 reactors
> I would say the CO2 injection only brings the pH down by about
> 0.2 - I haven't figured out a system for efficient diffusion yet,
> and it's a reasonably big tank.  At the moment I have 2x2l coke
> bottles (of which I make one new mixture each week) bubbling into
> one of the power filters. 
What kinda power filters is this? Maybe you have too much turbulence
and air/water interaction.

> The CO2 pretty much comes straight out
> in tiny bubbles, so it doesn't stay in contact with the water for
> that long.
Ah HA! No reactor explains why the Co2 isn't dissolving. I use a 
Whisper power filter which has a pump with a lift tube shaped like
an inverted U. I bubble into the uptake and this sends the bubbles
through the pump where they get thoroughly mixed very turbulently.
The bubbles tend to collect at the top of the U tube until there is
enough to get sucked into the pump. There is a flow control which
I dial to the lowest setting. I keep the water level in the 49 gal tank high
so all you see at the outlet of the filter is kind of a ripple, instead of
the little waterfall I used to have. This still gives enough O2 exchange
but minimizes the amount of Co2 which is released. The other thing;
I use glass covers. I find that I need only 1 Co2 bubble every 5 seconds
or so to maintain pH about 6.2. When I put a fresh sugar/yeast mixture
the bubble count goes over 1/sec and I dial up the flow on the filter
to try to dissipate it but the pH still tends to dive. The plants love it
and so far I have observed no change in the fish. The neons look great
in fact and don't mind low pH at all.

On the subject of importing the Apon. madagascariensis from Baltimore
to Vancouver; Peter and I are working on this. Wish us luck! :=)