Siphon failing

[mjust]

I've had my tank running for over a year and am yet to have this problem. As of the past few weeks I have to restart the siphon in my overflow about every three days. I clean the over flow once a month, change the floss in my sump at the same time. The return line has a ball valve, so I opened it just a bit more but that did not seem to help. Any ideas?

[Geoff]

are your siphon hoses clean? if they get algae growth in them they can slow down the flow of water in the tubes allowing air to collect at the top of the arch. this in turn slows the flow even more making the problem worse.

why do you have a valve on the drain?

G~