DIY under gravel filter
- Thread starter eon aquatics
- Start date
i would like to make one for a 120 gallon
it would require panels with holes in them or something and a pipe with a pipe fitting as well as a sponge of some kind and either a water pump or a air siphon
it would require panels with holes in them or something and a pipe with a pipe fitting as well as a sponge of some kind and either a water pump or a air siphon
can a canister filter intake be put under the gravel, in essence creating a under gravel filter
or does that require a screen/tubes with holes or something added on to the intake
or does that require a screen/tubes with holes or something added on to the intake
You'd definitely want a barrier in between the intake and substrate. Unless the gravel is very large even then I'm not sure that's a great idea. You can make a plenum/under gravel filter plate using egg crate and polyester window screen, using pvc pipes as a lifting structure. You could also use PVC as "stand pipes for air lift or a power head. You just need to use a substrate that's large enough to not pass through the screen.
So, you don't want a DIY filter...you want a SEDIFY (Someone Else Do It For You) filter?
The easiest way to build a UG filter is simply by supporting a sheet of lighting eggcrate above the bottom of the tank on a series of 1/2-inch PVC or similar. Cover it with a sheet of plastic window screen mesh to support the gravel. You can use one or more vertical lift tubes, powered either by air or powerheads, to circulate the water.
Or, much better, you can do the same thing but attach a piece of glass completely across one end of the tank, siliconed in place so that there is a half-inch gap across the bottom. The undergravel plate abuts the glass, so that the undergravel plenum is open to the chamber behind the glass sheet. Now you can use a canister or other filter set up to draw water from the tank above the gravel, filter the water mechanically to remove solid waste, and then return it to the narrow chamber behind the new glass sheet, so that the filtered water now flows downward, under the gravel and then up through it. This reverse-flow idea keeps the gravel much cleaner, so that it functions much better as biomedia without becoming quickly clogged with solids.
The vertical chamber behind the glass sheet is a great place to install heaters, etc. to keep them out of the display portion of the tank. I had a number of tanks filtered this way back in the day, and they worked very well. I used Aquaclear 500 HOB's, mounted at the end of the tank with the vertical chamber and with their intakes replaced with DIY PVC extended ones to draw water from the far end of the tank.
Take some pics when you get it all set up.
Last edited: