Reverse flow undergravel filter

[peterp63]

Does anyone have any experience with reverse-flow undergravel filters?  

I have heard that they work really good.  Basically eliminating the dead spots often seen when using a traditional undergravel filter.  These work by forcing water UP through the gravel.  Both utilize the surface area of the gravel for biological filtration.  The ones that I've seen and read about use PVC pipe with T's and elbows to cover the entire bottom of the tank with holes drilled the length.  A return pump from a sump or canister filter pushes the water through the PVC pipe, up through the gravel, and theoretically spreading across the entire gravel bed.

Anybody????

[Zulaab]

Re: Reverse flow undergravel filter

I have not used it.. but I see it being a potential problem with regards to how waste products would be handled.    I am sure that someone like MikewhoTroung will jump in shortly and give us all a good explanation.

[eklikewhoa]

Re: Reverse flow undergravel filter

The one's you are describing is the UGJ- under gravel jets....meant to keep from having dead spots primarily.

[CichlidFan]

Re: Reverse flow undergravel filter

Well, as I see it, there would be a need for some good filtration inside the tank as well to capture the floating waste and other debris. It would be only partially effective in my opinion, not 100% as far as keeping all solid waste particals from gathering on the substrate...guess that's where the cats and loaches come in eh?

But I can see where in theory it might could work if done properly in conjuntion with the appropriate inside filtration.

CF

[RussGB]

Re: Reverse flow undergravel filter

I did a lot of research a while back while I was settign up my 150g. I was going to do it, with an intake at the top and a cannister then down into a RFUG. The ones I saw were conversion kits for the traditionlal UG plates... The theories seemed sound but it does not remove dead spots; thicker areas of gravel will have slower flow or no flow, and rocks and wood will disrupt things too. Also they still play havoc with most plants. In the end I went for a pair of HOBs and a cannister.

[nacra99]

Re: Reverse flow undergravel filter

Personally, i don't really like UGF's (reverse or otherwise). They are nitrate factories which you can't easily pull out and rinse.
The only exception is if you are heavily planted of if you do very frequent waterchanges. Then you want the conventional UGF instead of the reverse flow UGF. Otherwise the flow of the water through the sediment may prevent plants from being anchored to the substrate easily.

[jklntx]

Re: Reverse flow undergravel filter

I used RF for a year on a 55. What I found was the lack of silt that forms under the plates found with standard UG. Also. many fish love it because it keeps food at surface of substrate without being sucked below. It can bother some bottom dwellers however as the upward flow is irritating. I used gravel..I would not recommend RF with sand substrate for that reason.

It also makes it very easy to clean the substrate because most everything stays near top and is not sucked under plates as described earlier.

I never had ammonia, nitrate nor nitrite issues. But keep in mind I focus on SA dwarfs, not Africans which create a heck of a bioload so I dont know how effective UF would be with larger waste producing fish.

Also, I did not use it with a planted tank. As described above RF will interfere with the rooting system.

I removed mine eventually because I wanted to utilize Eheim canisters and Emperor HOB and using with RF was overkill.

So as with any time you ask for suggestions in this hobby...it depends......