How does the under gravel filter work????

It works in a similar way to a sponge filter. There probably is a hole or plastic tube for you to put a air line tub into. You put the tube in there and as the bubbles go up the tube it draws water up with it, the water then passes through (normally in my UGF at least) a small bit of activated carbon. But it draws debris/poop etc under the filter and away from fish.

Here, this should help:



If I were you, I'd switch to a small sponge filter instead. UGF's are incredibly dirty, imo. a bunch of food and feces gets stuck underneath the plates and you'll never be able to reach them.

Sometimes people use power heads on top of their tubes for ugf instead of the bubbles. Moves a lot more water at a faster rate. But I agree, even though my lfs swears by their under gravel filters, I think they probably get clogged with feces and food, then all of the water would flow past that making it more dirty.

They don't, use a real filter, even a nice little sponge filter.

UGF's work well if you know how to use them. They are very simple in design and use and have been around since it seems like forever.

You can power them with an air pump (see above post) or you can use a powerhead to pull the water through the grates. A RUGF (Reverse Undergravel Filter) set up is where you push the water through it and have it exit the gravel bed grates.

reptileguy2727 said:

They don't, use a real filter, even a nice little sponge filter.

Click to expand...

Lol. What he said.

An UGF, even RUGF, is a good way to create a lot of unnecessary work for yourself that will still mot likely end up being a horrible mess of a mistake.

If you have ever broken down a tank that had an UGF you will know what I mean. I have seen them where it looks like the city was pumping its sewage through the tank.

It is pointless anyways, sand is a much better substrate than gravel anyways. It is a lot cleaner, a lot more natural, and looks better.

IMHO, UGFs aren't the worlds greatest filter, but if done properly they can work. I also like that sound of RUGFs, they wouldn't get clogged up as the water is pushing everything out of the substrate. Each to their own, and I don't personally have one (they don't make them big enough for my tanks )