Building a sump

[sandy]

My upstairs neighbor builds tanks. I saw a couple of 120gal tanks he built. Looked good, ran well.
He has freshwater... so I was thinking about giving him my new Fluval 304 in exchange for building an overflow sump/ref, whatever.
Who here has built an overflow sump? Meaning DID NOT have the tank drained and drilled? The LFS said that it is guaranteed that if I build an overflow that it WILL cause problems, overflow out of the tank...
What do ya think? I have a 20 gal I'd like to put under the Main tank and have him do the work... depending on his references.

 

[rapt0r32]

Sandy,
I have built an over flow with out "draining the tank". It is a 30 gallon rubbermaid sump. I got some ideas from Broomer. He helped me out alot. I used his website ( of his sump pics) for ideas. I am sure his link is posted on one of these threads. I hope to have mine posted shortly.
Rapt0r

 

[wamp]

Sandy,
I assume your talking about a Hang On overflow? I added one to one of my 55 gallon tanks I used to have with no problems whatsoever. I did drain the tank a little, about 2", so I could get my level in the sump and tank right. You need to make sure if power goes out your sump will not overflow. Most people just unplug the return pump to make sure this won't happen.
Good Luck!