Koi Rescue
Phoenix Arizona

ShortyPen Barrel Filter 2

The first version of the barrel filter is very simple to make, but one big fault is that it produces a lot of foam which rises to the top and sits on top of the bioballs. There are many different types of foam fractionators / protein skimmers to produce and remove foam, many of them are seperate from the main filter and require their own water pump or air pump. I wanted a simple way to remove the foam which worked inline with the existing circulation pump, so I didn't have to spend extra watts on a seperate pump. Producing and removing the foam also takes various dissolved organics from the water by having the particles stick to the bubbles as they rise.

The diagram to the right is what I came up with, it sort of mimics other filters I have seen, but is more of a simple addition to my barrel filter. The water flows down the tower pipe which is filled with golf wiffle balls, this creates the foam. The water flow carries the foam bubbles down to the bottom of the pipe, very similar to the way the Mythbusters fed ping pong balls down a long tube when they were trying to recover a sunken boat. Then as the water flow turns, the foam has an opportunity to rise up the escape tube.

Start by making the lower section of the tower pipe. I used a dremel to cut a hole in the side of the pipe near where the bottom is.

Its a pretty sloppy fit, and is not sealed perfectly tight, but does the job. I use zip ties to hole the 2" Tee to the 4" tower pipe.

Add an end cap to the 4" pipe, and add the foam escape tube.

To make the water return from the barrel, I use a shower drain which is commonly available from Home Depot.

I remove the grate, then sand the interior so I can glue a piece of 2" pipe all the way through the fitting. This lets me slip fit other fittings onto each side.

Here is my water return strainer. The elbow and extra piece on the end is an overflow incase the long section gets plugged up.

This is the upper section of the tower pipe which is filled with golf ball wiffle balls. Each ball is a hollow plastic ball with holes in it. They seem to do a great job of ripping apart the water and highly aerating them.

To keep the golf balls in place, I tie a larger wiffle ball on a string, and it hangs inside the pipe.

Here are the parts assembled and inside the barrel.

Another picture of the barrel filter assembled with the parts.

This sort of shows how the water flows. The blue is the water, and the red arrow is the foam escaping in the vertical pipe.

NOTE: I haven't put the bioballs in yet, was just running it empty like this to try and snap a picture of the water flowing around. I then put bioballs in there and fill it about 2/3 of the way. The bioballs float, so it leaves a gap in the bottom which acts like a settlement chamber before the water flows up thru the bioballs. You can use all sorts of media instead - like pot scrubbers, hair curlers, PVC shavings, sponges, or whatever your favorite media is as long as it floats.

The barrel in action.

This is the foam being produced, and removed. You can see that some of the foam remains in the barrel, but most gets ported out and drops into the bucket.

Mmmmmm..... tasty.....