How does an underground filter work?

Question

How does an underground aquarium filter work? I've heard they don't work as well, and I'm curious why?

Answer 1

not sure and they dont work well they only work with a air pump it not sure why  

Answer 2

Form what Ive heard, I think they work similar to a sponge filter. I believe that the air pump somehow pulls the water over the top of the tubes, also forcing the water to go through the gravel and the underground filter plate. A disadvantage is in the fact that it does trap waste in the gravel. However, by vacuuming the gravel regularly, this becomes a non-issue.

Answer 3

Undergravel filters work very well if equipped right. I used powerheads on my u.g. filter. It works by cycling the water through the gravel, where bacteria start to form. This bacteria then filters your system by converting ammonia and nitrites to nitrate.You still need to do water changes to remove the nitrate. Most people I have seen under-power the u.g. filter by using underrated air pumps.******* Just want to add.. that the waste that collects under the u.g. filter is easily cleaned by putting a siphon hose down one of the lift tubes and clean it out. This can be done  when you clean your gravel on a regular basis. This however is not only filter I would rely on. You still need chemical(charcoal or other)filtering and mechanical (hang on back of tank) or a magnum,Eheim ect. that do both mechanical(removing of the particles in the water) and Chemical(carbon absorbing bad toxins). I use both,can never have too much filtering.

Answer 4

if your curious so you can have one in your tank i will tell you know they are definitely worse!

The problem with underground filter is that it traps waste underneath the gravel which is very bad as it will cause the nitrate and nitrite levels to be thought the roof!!! With this being said you often have to remove the under gravel filter so you can siphon right down to the bottom of the tank.

As for how it works. it works the exact same way as a hang on with activated carbon, sponge, and ammonia removers........

So hopefully you aren't planning on going out to purchase one of these filters, and if you already have on i would suggest replacing it with a hang on filter (also undergrounds are harder to change the filter cartridges)

Hope this helps :)

Answer 5

Hi,

Yeah, they work brilliantly, they're a bit old fashioned know but still good in my opinion. Only trouble is because they suck the muck down through the gravel then the gravel gets dirty faster than normal.

Answer 6

day very good day suck any leavings into the ground day very good  

Answer 7

try this site go to undergravel filters

http://www.americanaquariumproducts.com/...

it should help u out and good luck :)

Answer 8

Undergravel filters do work, but they have some serious limitations.

First off is that the filter media is just gravel, So it doens't have a great surface area or high flow rate to encourage lots of cycle bacteria.

2nd is that they can eventually fill up with crud and you have to strip down the tank to clean things out properly.

But they do work, the water gets sucked down through the gravel and so the whole gravel works as a biofilter and creates the nitrogen cycle your tank needs.

But I suggest you get a small power filter as well, and run both types.

Ian