Do U Use The Old Method

[007_gaz]

does anyone use the old way to filter by having a tray under your gravel. some say if maintained well by gravel cleaning oftern its a very good filter. i heard it only works best if u have thick layer say inch layer of gravel on top of tray. i think internal filters are better though as they can catch floating bits. can u use internal filter and a tray filter together thats like a combined effort there. with that old tray it seems good as all of the gravel is the surface where bacteria grows and thats alot space compaired to small filter sponges.

 

[spongy]

I used to years ago with my first tank but I've now got an external, I found with the under gravel filter it was fine until my plants had matured and their roots had completely clogged up and grown around the undergravel filter.

 

[Essjay]

There's a very infomative post by nmonks on UG filters here in post #11
http/www.fishforum...ters-yes-or-no/

 

[007_gaz]

i was wondering can just gravel alone act as a filter. i think in the wild this is the case and the moving water is the water change. see i have a tank thats bare bottom and its easy to clean but i was told u need something on bottom as it acts as a filter. is that true that gravel on its on is the filter. i thought all the good bacteria u find on the sponges inside the internal filters is where all the action is.

 

[Essjay]

When the tank has an internal filter - or an external or HOB or trickle filter - the vast majority of the bacteria live on the media inside the filter. The reason is that the bacteria like to live in places where there is a good water flow bringing lots of food and oxygen, and the filter has the best water flow in the tank. The media has also be designed to have a huge surface area in a small space, whether that's the surface of the bubbles in a sponge or the rough surface of ceramic media etc.
In a tank with these filters there will be some bacteria growing on every surface in the tank, but compared to that amount living on the filter media only a small amount. From a filtration point of view, so long as you have an internal, external etc filter, a bare bottomed tank is fine.

Gravel alone can be used as a filter as in an undergravel filter, which works by having the water flowing through the gravel. But with an internal filter, the water just flows over the top of the gravel not through it.