11. At certain flow rates, a flushing noise coming from the overflow may occur. This noise is caused by air
trying to escape back up through the bulkhead while the water is going down. A 3/16” standard airline
tube fed down through the bulkhead fitting will vent this air and reduce the flushing or gurgling sound.
You may need to adjust the level of the tubing up or down to find the point where the air is vented.
Your overflow is now in operation
The outside of your overflow may be cleaned with a non-abrasive cloth. Do not use detergent on any
surface that comes into contact with aquarium water.
Note: The CS150 does not include the sponge and vent tube seen in the diagrams below.
Fig. 1
Fig. 2
Fig. 3
NOTE: No slip
screen, vent tube or
gear sponge is in-
cluded with the
CS150.
