Many people need some way to slow down the current of a filter, whether because their fish are being thrown around in it or because their betta, a species notorious for their hatred of water currents, despised it. I have had the same problem, and designed a system to help alleviate it.
Stopping the spectre
The vast majority of filters sold in the US are of the Hang-on-Back type. These typically have a 'waterfall-outlet,' where the water falls down out of the filter into the tank. The obvious problem is that as the water falls from the outlet, it accelerates under the force of gravity until it reaches the waterline, then creating a strong current.
The secret to stopping the current is to simply obstruct it. The most efficient way to do this is to use the body of a half-liter soda bottle. I will now describe how to construct the device.
Step 1: Start the incision...
You must first cut the soda bottle appropriately to prepare it for mounting. On the right, you will see a diagram for the first cuts, labelled "Cut 1." You must remove the two ends of the bottle, leaving only a smooth cylinder from the center of the bottle. Next, you need to tear off the label and cut the cylinder along its length, right next to the strip of glue, as shown in diagram "Cut2." You should now have a simple sheet of curled-up plastic.
Step 2: Duct Tape and BubbleGum
This step is very simple: simply tape one end of your plastic sheet - the end with the glue on it - to the top of the filter, and bring the other end around under the outflow, as pictured at left. (I outlined the edge of the sheet so you can tell where it goes) Then you're done, go play in traffic or something.
Name: Joe Comments: Great system! I tried this out on my ten gallon tank and it works perfectly. I set it up so the water streams are deflected out the sides of the plastic. Amazingly simple, yet it works.