Basic sump/ref setup

[jinenon]

I now have an awesome setup going and havent lost anything since i put the sand substrate in. My only concern is that i cant get my nitrates below 40. I have a 30 gallon tank and im ready to get a sump going. I cant drill my tank so i would love some input on sump setups and any diagrams with flow and an explanation of how it works would be great. Thanks guys