Undergravel filters
- Thread starter Malbri
- Start date
they circulate water via airstones airating the water in the tubes to make it lighter so it rises or by power head witch is just a pump, and it sucks water under the gravel and uses the gravel as bio media like say biomax in a filter. depending on the size of the tank you can filter the tank competly of this. ive seen it done up to 20gals.
An undergravel filter, or reverse undergravel filter as Corbin described, are only a means of biological filtration. You'll need a HOB, cannister, or some other filter for mechanical filtration. Otherwise you're just shooting debris into the water column and circulating it around.
Keep in mind that if you don't use reverse flow UGF with power heads pushing debris up and out from under the gravel, that you'll need to be breaking the tank down to clean under the filter plates every so often as massive amounts of waste will collect under there no matter how thoroughly you try to vacuum. It's not fun.
You could always set it up with the power heads and keep the air pumps as a backup if the power goes out.
You could always set it up with the power heads and keep the air pumps as a backup if the power goes out.
Malbri said:
yes i do this.
webcricket said:
well you wouldnt need a mechanical filter if you did often water changes and syphon'd the waste out. my favorite LFS does this on a most of the small tanks and there running great.
First off: UGF sucks water down through the gravel and then up the uplift tube. RUGF sucks water from the tank, pushes it down the uplift tube and then up through the gravel. both make excellent bio-filters when used and maintained properly. Both should be used with a medium sized gravel that is 2.5-3 inches deep.
With the UGF you need to vacuum religiously to prevent glogging- both of the flow though the gravel and then through the plate. A 2nd filter is also a good idea for mech and/or chemical filtration.
With the RUGF, you need to sponge the powerhead intake- the sponge will provide some mech filtration and additional space for biofiltration. The advantage to the RUGF is it doesn't suck debris down into the gravel but pushes them back up into the water. By adding a 2nd filter for mechanical, the debris can be filtered out and you actually have to vacuum the tank much less.
The second filter can be an HOB or an internal. In larger tanks a canister can even be used.
With the UGF you need to vacuum religiously to prevent glogging- both of the flow though the gravel and then through the plate. A 2nd filter is also a good idea for mech and/or chemical filtration.
With the RUGF, you need to sponge the powerhead intake- the sponge will provide some mech filtration and additional space for biofiltration. The advantage to the RUGF is it doesn't suck debris down into the gravel but pushes them back up into the water. By adding a 2nd filter for mechanical, the debris can be filtered out and you actually have to vacuum the tank much less.
The second filter can be an HOB or an internal. In larger tanks a canister can even be used.
This is a false statement that continues to be presented as fact. The only time massive amounts of debri collect under the plates, is from a repetitive disregard for tank maintenance over a long period of time, usually coupled with overfeeding.webcricket said:
UGF's and RUGF's need cleaning just as much as canisters and HOB's do. No filter is free from some work. I would agree that a RUGF is a better choice as it makes the work easier than a UGF does.