Under gravel cleaners

[0sprey]

My bad, sorry.
I don't often recommend plants with UGFs, although I have done it in the past. UGFs force plants to spend too much time developing tiny little roots that don't absorb nutrients very well. Once the plate gets clogged there are some nice nutrient pockets for them, but by that time, the UGF isn't doing much good anymore.
What kind of plants are you planning on?

[RedneckDaveAb]

I used to have underground filters and they appear to have worked fine although in our fish club I have heard bad reviews

We now use Aquaclear filters without any problems. They are easy to clean and work well.

Hope this helps!
Dave

[PixSell]

Hi There;

I know this is an old thread but, I’m new, so here is my $0.02.

Do undergravel filters work?
Yes, absolutely!

Are there more efficient forms of biological filteration?
Yes, absolutely!

I’ve been using UG filters successfully for about 25 years on a variety of aquarium set-ups; sometimes as the sole means of filtration and sometimes with some other sort of power filter. Hang on back, canister & wet/dry trickle are, or can be set-up to be more efficient biological filters than UGFs. If you are going to have gravel in your tank anyway, you might as well have it being used to aid in the tank’s filtration.

In my opinion the LFS trade has turned away from them because they don’t make as much money on a (fully functional) UG filter as they would on a more expensive powerfilter. I recently had the owner of a LFS tell me (when I was trying to find an airlift tube for my UGF) to “get rid of that useless undergravel filter”. Well that “useless filter” had been keeping the same tank clean and the water in perfect condition for over 10 years.

I now have a 75g tank set up filtered mainly by an UGF driven by 2 powerheads. There is also a small AquaClear filter with a sponge (to catch some of the big floatie garbage) and a sock filled with peat (for Discus water quality). It’s pretty simple and it works. I have medium fine gravel on the bottom (next to the filter) and finer, coarse sand on top of that. The substrate is 3 to 4 inches deep. UGFs work better with lots of gravel.

Keeping Discus, I do, do a lot of water changing though; and vacuuming the gravel when the changes happen. The changes are 20 to 25% (sometimes more) twice a week. You have to keep the substrate fairly free of debris in order for UGF to work properly. If the UGF becomes clogged, the oxygen that the beneficial bacteria need to survive and do their job can’t get to them and they die.

That being said, a word of caution… Do not stop the flow of water (oxygen) through a UGF in an established tank. Your water quality will quickly turn toxic. If you want to stop using a UFG, tear the tank down; clean the gravel thoroughly to remove all the small decaying organic matter that is inevitably lodged in the substrate and under the filter plated by the UGF. Then put it all back together without the UGF.

I keep many plants with UGFs. I just plant them in small clay pots with a fertilizer pellet and peat in the bottom of it and some of the aquarium’s sand on top of that. Then I bury the whole pot in the aquarium’s substrate.

Hope that's somewhat useful, Chris

[jvision]

The only reason I switched out my UG filters from my planted tanks was that the roots would get tangled up in the filter plate. PixSell makes a good point - if you put the plants in pots, then you don't have to worry about the roots. However, that may impede the growth and spreading of some plants.