Powerhead/Undergravel Filter Question

[jmeunier]

So I've recently gotten bitten by the aquarium bug after about 10 years away, and just today upgraded from the 10G FW (that I promised my wife I'd **NEVER** need anything bigger than ) to a 30G FW that I keep at room temp. I'm only keeping goldfish now, and they seem to be thriving quite nicely.

For the new tank, I installed an undergravel filter along with a powerhead to move water through it. My question relates to the direction that I should have the water flowing. Should it be moving the water down the tube, and up through the gravel, or down through the gravel, up through the tube? The reason I ask is that it seems that it's meant to be run with water being drawn down through the gravel. My brother-in-law has a 55G FW tank set up that has the powerheads moving the water up through the gravel, keeping particles circulating and cleaned by the external filter. His tank is sparkling, so that's the way I've got mine running right now.


So, which way should I run it, or does it matter, or are there advantages/disadvantages to each?

Thanks in advance!
Jay

[fish_doc]

Sorry to tell you but if the goldfish get big enough they will start moving enough of the gravel to expose parts of the undergravel filter. When this happens the filter does not work properly because water takes the path of least resistance. So the water will not go through the gravel at all. Looking beyond that information if you keep a close enough eye on this and keep the gravel even over the bottom plate. The best way is probably to go down through the gravel and up through the liftertubes if you do not have a HOB filter. This will draw the debris to the bottom of the tank. If you have a HOB filter then reverse it so it draws water down the liftertubes and up through the gravel. This will cause the waste in the tank to float so the HOB can filter it out of the tank.

[smooth_rivers]

what doc said, unless you have the power heads with the sponge filters attached (IE the penguin 660R) Then it'll get sucked into the sponges.

[Terry]

If you have an UGF which has a powerhead the water is being drawn through the gravel and up the tubes, if you are useing the UGF with an external power filter you can push the water down the tubes and up through the gravel and let the power filter remove the waste. This is called reverse flow.

[TankGirl]

Reverse flow will prevent material becoming trapped beneath the UGF and decomposing, which is a plus in my book!