Pond Foam Separator/Protein Skimmer by Bubblemac Industries, Inc. The Bubblemac FS-KW1 was originally designed by Ken Williams in the 1980's and is intended to simply hang inside the top end of your tank and remove proteins by producing a foam discharge. There are many other high-tech, high-priced products that are available on the market today; none however that outperform this old farm-boy design. Comes complete with a one year warranty and the Bubblemac "LOVE IT" or "RETURN IT" guarantee! HOW IT WORKS: In the lower section of the white pipe, a Bubblemac fine pore 1.5" cube air diffuser produces small bubbles. These bubbles create foam out of protein buildup in the water. The rising bubbles create an airlift within the pipe, exhausting the water out through the side vent hole {shown in picture}, and discharging foam up and out the top. Use the blue string to hang the FS-KW1 unit to the side of the fish tank. Submerge the unit until the blue octagonal top plate is about an inch from the water surface, and secure. Deliver 0.4 CFM @ 1.5 psi to the 1/4" ID air line for the air diffuser. This protein skimmer works best in salt water or freshwater with a slightly higher pH level. Some users may find adding a small amount of Stress Coat or dried allbumin may improve conditions for foam production. We recommend placing a bucket under the discharge tube to collect waste for daily measure and notes. It is common to experience more buildup at night. These units are modular and proven to perform under continuous operation for up to 500 pounds of fish. If your load is higher you may add another unit.