Under gravel filter

[NewObsession]

So how exactly does an Under Gravel Filter work? I bought one for each of the 10 gallon tank kits I bought even though they come with a HOB (Hang on back?) filter. Overkill? I figure there's no such thing as TOO much filtration..right? How exactly do they work? Do I need to worry about uneven levels of gravel or where ornaments are placed?

 

[Rbishop]

The UGF uses the substrate (gravel) as the filter media. With an air driven UGF, the water in the lift tube becomes less dense than the water outside the tube. Since water seeks its own level, the water in the tank will flow down thru the substrate, under the plates, and up the tubes, back out into the tank.

This flow can be increased by having a powerhead on the lift tube, to pull a greater volume of water thru the substrate. Or by connecting a HOB/cnaister suction to the lift tube.

The use of the UGF requires a regular schedule of gravel vacs to keep the substrate clean.

The trend lately is to run RUGF (reverse ugf). In this type, a powerhead is connected to the lift tube so it's discharge is pushing water down the tube, under the plates, and back up thru the substrate. Or by taking a canister discharge to the tube.

This still utilizes the substrate as media for the biological filtration and pushes debri out of the substrate, into the water column, to be removed by mechanical filtration.

The gravel depth varying does affect the flow, but I do not think it is really a concern.

 

[nickmcmechan]

i like ugf because it is efficient and effective, there are downsides, but it must be the best value for money filtration you can buy

 

[Phil22]

After many years with an air driven ugf, I've essentially stopped using them. They're noisy, the air stones clog up, and I'm not sure how effective they are anyway. I'd heed rbishop's comments regarding using either a powerhead for the ugf, or better yet, a RUGF.

 

[vidiots]

After many years with an air driven ugf, I've essentially stopped using them. They're noisy, the air stones clog up, and I'm not sure how effective they are anyway. I'd heed rbishop's comments regarding using either a powerhead for the ugf, or better yet, a RUGF.

UGFs run off a submerged powerhead with the air intake disconnected or turned off are the quietest filters I've come across todate. I too have never liked the sound of running or bubbling water or the sound of a humming air pump.

Like all other filters they have their good points and bad points. The same is true of the RUGF, HOB, Sump, Internal, Canister, it just all depends on the application as to which will workout the best.

 

[red devil]

If you put ornaments in your tank and u use a ugf you should move them periodically when you are vacuuming the gravel to vacuum under them. I put a plug in for rugf filters also - I use them in all my tanks. I also usually use a hob filter as well. Yes, I don't think it is possible to overfilter water. The problem arises when you create so much current in the process that the fish get stressed.

 

[NewObsession]

My other question is this: the 10 gallon UGF come with two plates and 2 uplift tubes. I knocked out the centre partion and ran both uplift tubes. I am now wondering if I should have left the partition in if running both tubes, or if they are joined could you just run one tube ( especially with a power head, although the back of the tank is getting a little crowded since its a 10 gallon)?

 

[red devil]

when I did rugf I always used all the uplift tubs and connected them with pvc so that there was only one uplift tube.

 

[chunkoblue]

I've found them to work well, but I don't like the tubes in the corners of the tank because it makes it more difficult to clean back there.. I suppose I could take them out before I clean the glass... Blah!