Thin Film Surface Skimming Adjustable Standpipe

The Thin Film Surface Skimming Adjustable Standpipe has a one inch standpipe core and a two inch exterior that can slide up and down on the core to make fine adjustments. It is made with a 2 x 1 inch bushings with the stop ground out so it can slide up and down on the one inch standpipe for fine tuning. The bushing is inserted into a two inch coupling. The other end of the coupling has a 4 inch length of 2 inch pipe which becomes the top of the surface skimmer. To prevent fish from going over the standpipe a one inch bulkhead intake screen is inserted into a one inch couple or cap, inverted and inserted into the schedule 200 one inch stand pipe. This creates a 1/8 to 1/4 inch continuous gap between the one inch coupling and two inch pipe. This provides great thin film skimming.

Surface skimming is the most effective and simple way to remove the oily film of proteins and oils that build up on the water surface of heavily fed tanks. A clean surface is where your gas exchange takes place. A surface film significantly reduces gas exchange am carrying capacity of a tank.

Aeration is a great way to push the film back and break it up. This method leaves the fat and protein in the tank or splashed at the water line. Surface skimming removes it from the tank completely to be filtered.

For surface skimming to be effective you need thin film of water going over the standpipe. To handle the flow you need the surface area of a larger diameter pipe. A one inch stand pipe can handle the flow rate of this tank but skimming is in effective due to the small cross section of the pipe. With a two inch outer pipe acting as the weir the amount o linear surface area for skimming doubles.

Another key issue for surface skimming to work effectively is the water must drop over the first edge of the skimmer a sufficient
distance so skimmed film doesn't backup on the surface tension stopping the skimming.