I've been keeping fish for the better part of 15 years now. In every single on of my setups, I've ALWAYS had an undergravel filter. I also have always had at minimum, 2 hangover filters to supplement the undergravel filter. Every single time, it never fails.

Lately I have been reading a lot of articles on UG filters being in-effective. However, experience has proved otherwise for me, as I have never ever had an issue with water quality, and I think I've had maybe 1 or 2 fish ever die on me for no apparent reason (I consider water quality no apparent reason).

What are your thoughts on this?

I've read some of the threads, and I know a lot of people opt against UG filters because Oscars dig. My big boys dig once in a while, but for the most part they leave it alone. Let me know what you think. Do you think I'm wasting my time with a UG filter? I certainly don't, I just want some other opinions.

Also, to clarify, I would never, EVER use a UG filter as my ONLY and primary source of filtration. That always has been, and always will be either a canister or a hangover filter. Just wanted to see what you thought of them as a supplement, and their uses as a whole.

A standard UGF with an air stone in the uplift tube work well with fish like community fish but only if you maintain them well. They clog up if you dont clean them often enough and if you clean them too often you can remove too much bacteria. UGF's dont work well with Oscars because of the amount of waste they produce and also because they dig. If they dig down to the UGF plate, the UGF wont work

What i do is get the output of an external cannister filter and this goes down the UGF uplift tube. The means the water circulates down the tube and up the gravel (opposite to when using an air stone) which means it doesnt get blocked. An alternative to using a cannister is to use a power head to push water down the tube. To stop oscars digging i have a gravel tidy (a sheet with holes in). I use an UGF to reduce the need for gravel cleaning, any extra filtration is a bonus

Guess I probably should have clarified that. Yeah, I use 2 powerheads hooked up to the UGF, instead of airstones. I like powerheads a lot.

Your theory is interesting with the canister filter though.

Also, digging isn't a problem for me, like I said. Mine rarely dig.

I could easily swap the output from a cannister for a power head to 'run' the UGF and the cannister output could then flow back into the tank. The effect would be the same. I used a cannister because i already had it and it saves buying a powerhead. Remember you still need to ripple the surface, so if you are using a cannister to do this and you use in on a UGf then you will need to buy soemthing to ripple the surface, like an air pump or powerhead

I myself have never used an under gravel filter. I think you have already mentioned one reason why they are probably not the best filters to use. My Oscars are for ever exposing the bottom of the tank.I also wonder how well they remove large solid waste. The only time I have seen these filters is in small community tanks. If you're going to set a tank up for an Oscar then you really should be looking at large powerful filtration.

They aren't very good at removing large waste at all. Hence, why a UG isn't my primary filtration.

I am running an AquaClear 110 (500 GPh), Emperor 400 (400 GPh), and 2 Powerheads on the UG filter at 170 GPh each.

So I'm well over 1,200 GPh in the filtration department. When I buy my new house, I'm picking up a Fluval FX5 and I'm gonna do a DIY Background. Right now that's the best I got though.

Filtration isn't an issue for me, I just wanted opinions.

I wouldent bother with UGF to be honest ...Fluval FX5 = legend

STAFFIE wrote:


^^ ditto, the money that I spent on my fx5 was definitely a good move the filter is amazing.

I like under gravel filters while keeping in mind that they don't filter anything at all. I strictly use them as aeration for my tank by either air stones or power heads. I don't have many issues with digging with my O's. My Jack Dempseys used to dig big holes in the bottom. Not so much with my O's. I have 2 Jebo 835's filtering 264 gph each and 2 aqua-tech 30-60 hob filters in my 125 at the moment. The 2 hob filters are just temporary because I just moved the tank. My 90 gallon has a Jebo 838 filtering 315 gph. Both tanks I have ugf's in. Air stones on 4 tubes in the 125 and 2 power heads in the 90. I like it set up this way. Just a personal preference.

every filtration has it own advantages and disadvantages.... i love UGF
especially the liquefied effect if you used it in reverse mode. yes, i
normally used powerhead instead of air pump to move the water around.
employing a mild current at the bottom keep all craps at the suction
point, thus, no unsightly crap inside my tank at all times....

however, i find it impractical to use a UGF in a 6 ft x 30"wide tank..
it can only cover so much space as it has limited size....

PAUL wrote:


For my 180g (6ft long x 32in deep) I connected several UGF's together (due to the shape I could overlap them) and filled in the uplift tubes except one on each end

cave men had clubs to fight with, they worked well(at the time) but then came along the gun. would you have a gun or club nowadays.

they have there place and work fine in small tanks with small fish. are you wasting your time? NO if its working for you, why change? I believe a large canister cannot be replaced by a gravel filter for large fish. I have seen them clog up and leave gravel looking like a toilet. if money was no object I would go with a large canister for tanks up to 200g (UK). if I was going to use a under gravel system I would reverse its flow.