View Full Version : plenum filter

09-10-2003, 11:22 AM
I wonder if anyone has any experience with a plenum filter. This is simply a piece of foam egg crate that covers the entire bottom of the tank. the egg crate is held up off the tank bottom by small lengths of pvc pipe and is covered by two layers of nylon mesh to keep fish from disturbing the filter. It works by metabolizing nitrates with bacteria. has anyone heard of this? Apparently a lot of marine aquariums are being set up with them. they may not be suited to africans because of the digging issue.

09-11-2003, 05:39 PM
i have never heard of that. It sounds pretty kool to me.

Freddy J
09-11-2003, 05:47 PM
It's the same theory as the under gravel filtration. The mesh over the egg crate will prevent the digging from disturbing the function of the filter. garf.org for more info.

09-11-2003, 06:42 PM
i think there is a big diffference between the old UGF and the plenum filter. the plenum filter
grows bacteria which eliminate nitrates, whilst the UGF pulls waste into the gravel and metabolizes ammonia and nitrites to nitrates. I
just wondered if anyone has used them for cichlids

10-07-2003, 09:46 AM
Ferdelance is correct......... the plenum works in a different manner than does an UGF.

The plenum method is utilized to create anaerobic (i.e. no oxygen) areas in an effort to colonize organisms that metabolize nitrate into free nitrogen, etc. The goal is to control and reduce nitrate. Since nitrate can easily be removed from a freshwater tank with water changes, research into plenum use on FW tanks is minimal. However, the complications of changing salt water makes the use of plenums valuable......... anything to reduce salt mixing, r.o. water, etc!

11-19-2003, 04:09 AM
with the use of a plenum, anaerobic bacteria does break down the nitrates present in the system, though i hear sometimes it can cause phosphates to increase. In this case the simple addition of caulerpa to utilize the phosphates would keep not only those under control, but also water changes and overall maintainance down to a minimal, reasonable, and acceptable rate.

11-19-2003, 11:54 AM
Caulerpa is marine though, and I think he is speaking about FW.