Overflow Box

[mr.wilson]

If you are using a siphon box you should add an airline check valve on the top of the U tube so you can manually remove air bubbles or have it on a constant suction from a venturi on a powerhead or use a Tom Aqua Lifter water pump.

Having a strong flow through the U tube will help minimize bubbles. Limiting the overflow to a maximum of two U tubes will help keep velocity high and discourage the formation of air bubbles.

The outer box should have a standpipe that regulates the water level and keep the siphon primed when the return pump stops.

[sphelps]

be careful with things like airlines for tube bleeding, while the check valve is a good fail safe the line can sometimes become detached causing failure. You can stick airline up the tube to start the siphon and up it out after. Matching the flow properly will insure air bubbles don't build up, most smaller tanks only need one.

Also run the sump and display tank water level such that the pump runs dry before the display tank overflows in case of failure.