Betta Listserv - How to make your own Sponge Filter

One of the most frequently asked questions of newcomers is how to make a homemade sponge filter. Here are 2 ways :)
They're also easy to make: I buy cheap sponges from the LPS or LFS, large rectangles or cylinders, doesn't really matter as long as it's got enough body. Then cut out part of the sponge, enough to nestle an airstone in it without too much of the airstone sticking out. Then jab an exacto knife through the middle of the sponge, making a channel, of sorts, through which I stick airline tubing. Stick the airstone on the end of the airline tubing and voila, you have a sponge filter.	Making your own sponge filter is really easy. All you need to do is cause water to move through a sponge. One easy way is to join two pieces of 1/2" PVC pipe with a 90-degree elbow. One of the pieces of pipe needs to have a bunch of holes drilled in it and an end cap (on the end). The piece with the holes is wrapped in 1/2" or 1" foam. I hold the foam in place with cable ties. The foam covered arm sits on the bottom of the tank, and you place an airline tubing down the other PVC to the elbow. An air stone increases the efficiency of the unit, but is not necessary. I buy my foam rubber, PVC pipe, and cable ties from the Do It Yourself store. You will find that this simple filter will cost almost a dollar and a half and is as efficient than anything you can buy . I also do much the same thin with a single piece of pipe with foam on the bottom half--but in shallow tanks that's not very efficient."
Cost breakdown :	Click for a full view of my quick sketch, lol :) It is DEFINITELY not to scale, but I wanted you all to have a general idea of what it was supposed to look like :)
Sponge - 3 for $3 - $4 (the Aquaclear replacement sponges work quite well, the come 3 to a box) Airstone - 1 for 59 - 99 cents Tubing - 2' or so for $1.50 (who doesn't hve extra of this laying around?) Total cost - $5.50 - $7.50 plus some time.