I'm trying to start small and need to get water out of the 20 gallon fish tank and down into the sump. Is there any siphon system that will work to get the water up and over the side of the aquarium without cutting a hole in the glass?

A no holes siphon will work but they arent totaly reliable and theres no fail safe if they dont work

Search for the No Holes Overflow thread. They can work but I don't really recommend them because they do need regular checking and I've had them fail on me. If you do go this method, I definitely recommend redundancy Go larger than you think you need and then have two of them.

Thanks for the info. I think I'll put the fish in a rubbermaid tub and cut a hole. It looks cheaper and easier than all those pvc parts.

Here is a post about no hole overflows. You might find something useful in there: viewtopic.php?f=8&t=4086

Cory

You could always set up a pump to start a siphon that goes over the side. Have the depth of the inlet as the setting point for the volume of water you want to move. Just run the pump enough to start the siphon would be the only tricky bit.