Under Gravel Filter

Hi

Sorry another question. I have a small tank with no filter at moment. I know under gravel are old school, but wonder if they still do the job? I have never used one but see them mentioned now and again.

Cheers.

David

Undergravel filters have their pros and cons

Pros -
Huge surface area - every particle of gravel

Cons -
Have to be used with gravel, they can't be used with sand
They have to be cleaned very thoroughly at each water change or muck will build up under the plate
If muck does build up, the whole thing has to be removed to clean it out
Rocks, wood etc can cause dead spots where water can't flow through properly
Modern ones tend to have flimsy (= easier to crack) plates unlike the original plates.


Did you know that biorbs use undergravel filters, and the rocks on the bottom are actually the biomedium?

Hi Sue

No i didn't will take a look. As it is such a small tank space is a thought. Trying to work out best solution for filter.

I had an undergravel filter in one of my previous tanks. I ran it in reverse flow mode using power heads to push the water up through the gravel bed. Found it was more efficient and didn’t require so much maintenance.

Undergravel filters have their pros and cons

Pros -
Huge surface area - every particle of gravel

Cons -
Have to be used with gravel, they can't be used with sand
They have to be cleaned very thoroughly at each water change or muck will build up under the plate
If muck does build up, the whole thing has to be removed to clean it out
Rocks, wood etc can cause dead spots where water can't flow through properly
Modern ones tend to have flimsy (= easier to crack) plates unlike the original plates.

Need to correct some incorrect myths here Sue...

1) It’s a common misconception that UG filters need more regular cleaning than other types. They don’t. As with other filters, they only NEED cleaning when the flow tails off. They certainly do not need cleaning at every water change.
2) They are they easiest type of filter to clean. Just use a gravel cleaner when you do a water change. You won’t get it all done so just do a half, third, whatever, and more at the next change.
3) They never need to be removed for cleaning. Mulm eventually accumulates under the plate. This is removed very simply by putting a siphon pipe down the uplift/s.
4) Decor doesn’t cause dead spots, just areas with reduced flow. These are not a problem, and rocks and wood can be moved occasionally in order to gravel clean underneath them.

5) Use Hagen or Rena interlocking ug plates. They’re incredibly strong and will not crack.

UGs are as efficient as any type of filter when used properly. Their only drawbacks are 1) The noise of the pump, 2) they’re not great with plants unless there’s several inches of gravel, 3) fish that dig will cause very mucky water...

My last undergravel filtration system used an external canister filter to 'push' the water down through the uplift tube(s) then up through the undergravel plate.
I seem to recall I siliconed the tubing from the filter into the uplift tube.
Using this method there was the added benefit of pre-filtration prior to the undergravel filtration stage.
I used this in a large cichlid tank and it worked extremely well.