Re: Filtration for 29 gal planted tank

Subject: HOT Magnums and CO2 injection

Well, this is the first time I've participated in this group, I hope I don't
do something that won't get me invited back!

> - -HOT Magnum; to which I might try to add a Eheim surface extractor.
> What concerns me is that it is rated at 250 gal/hr (though I think
> that is through empty box) and I might end up with too much water
> movement. I also have in mind using the Bio-Wheel adaptor (a tee) to
> split the outflow in two, one just above the bottom and the other one
> at the opposite end of the tank just below the surface, both slightly
> angled towards the front. Also, does anybody have any experience
> injecting CO2 in a HOT Magnum ? I'm concerned about the vapor lock
> possibility, like in the Fluvals.

I've been using two HOT Magnums on my planted 90G for a couple years now and
am very pleased with them. As long as the water level is high enough to cover
the water return tubes, they are virtually silent and do not agitate the
water surface. I don't inject the CO2 directly into the Magnums. I have a
diffuser placed under the intake of one, and about half the CO2 gets sucked
in where I assume some of it gets absorbed into the water, the rest gets
mixed in and distributed throughout the tank. The other half of the CO2
floats upwards, and gets kicked back down into the water from the return
tube. Some CO2 escapes directly to the surface. HOT magnums are great at "off
gassing" any excess air/CO2 that collects in the filter, and I've never had a
problem. I tried injecting CO2 directly into the filter once and it made an
irritating noise as each bubble got sucked in. I think my CO2 system is
probably wasteful, but a 5lb bottle easily maintains the pH at 6.8 at a KH of
6-7 for 8 or 9 months.