I needed a sponge filter for my fry tank and I wasn't really fond of the cost of buying them considering I felt I could make MANY filters for the cost of only a couple. One feature I wanted in my filters was the ability to take it apart to replace the air stone as needed and the ability to remove the foam to clean it or replace it.
You need 8-10" of 1/2" PVC pipe, 1 socket cap, 1 socket to threaded, 1 threaded to socket, 1 socket to threaded coupler, a few inches of silicone air tubing, small airstone, air tubing and piece of foam. I got enough fittings for 4 filters and enough foam for probably 20 filters for about $10. I bought 3" thick foam from Jo Ann Fabrics.
Wet the foam, squeezing as much air out as possible. Place the sponges into the freezer for a day or two. Remove the sponges and promptly cut to finial size while still frozen. Also drill a 3/4" hole in the center of the filter clean through before it thaws. Set the foam to the side.
Cut the 1/2" PVC to size. Slide the tubes into the threaded to socket coupler and mark where the edge of the PVC is. Slip the sponge onto the PVC and slide down to the coupler and mark where the top edge of the foam is. This is the area that will be drilled for water flow when the sponge is installed. Remove the sponge and drill some holes into the PVC pipe. I drilled about a dozen or so. Make sure you don't go outside the marked lines, in fact I try to leave a margin outside of the holes.
Drill a hole in the plug exactly the size of the air tubing that you are using. Start small and stop when the tube fits but is still tight. Now fish a short piece of tubing into the hole and up about 1 1/2" or so inside. Now you can install the air stone and put the fittings together.
Now you can install the PVC Pipe and slide the foam into place. Now you can use a air hose coupler to attach air tube to your air pump.
Make sure when you put it into the tank that you squeeze the air out. You can add a couple pebbles to the bottom of the unit if you need the weight.
Jim
You need 8-10" of 1/2" PVC pipe, 1 socket cap, 1 socket to threaded, 1 threaded to socket, 1 socket to threaded coupler, a few inches of silicone air tubing, small airstone, air tubing and piece of foam. I got enough fittings for 4 filters and enough foam for probably 20 filters for about $10. I bought 3" thick foam from Jo Ann Fabrics.
Wet the foam, squeezing as much air out as possible. Place the sponges into the freezer for a day or two. Remove the sponges and promptly cut to finial size while still frozen. Also drill a 3/4" hole in the center of the filter clean through before it thaws. Set the foam to the side.
Cut the 1/2" PVC to size. Slide the tubes into the threaded to socket coupler and mark where the edge of the PVC is. Slip the sponge onto the PVC and slide down to the coupler and mark where the top edge of the foam is. This is the area that will be drilled for water flow when the sponge is installed. Remove the sponge and drill some holes into the PVC pipe. I drilled about a dozen or so. Make sure you don't go outside the marked lines, in fact I try to leave a margin outside of the holes.
Drill a hole in the plug exactly the size of the air tubing that you are using. Start small and stop when the tube fits but is still tight. Now fish a short piece of tubing into the hole and up about 1 1/2" or so inside. Now you can install the air stone and put the fittings together.
Now you can install the PVC Pipe and slide the foam into place. Now you can use a air hose coupler to attach air tube to your air pump.
Make sure when you put it into the tank that you squeeze the air out. You can add a couple pebbles to the bottom of the unit if you need the weight.
Jim
