Originally Posted by
Scopus Tang
http:///forum/post/2484056
Peef, PM Dennis210, he can give you the specifics on drilling, hole sizes etc. He and I have had 6 20 gallons and 2 55 gallons drilled, and this weekend we're having a 120 drilled. I strongly recommend finding a good glass shop that will do the drill for you, rather than drilling it yourself - it'll cost you a little more, but worth it IMO. I agree with Bone, and while its empty and sitting is the time to have it done.
Right on! Get a glass shop to do it or someone with experience and you trust. You could do it yourself if you have the tools, but you would be seriously upset if you cracked the tank or something. Two 1.5" holes would probably be ideal and then get bulkheads with 1" ID (internal diameter) holes for your drain and return. Shoot for a return pump that will deliver ~400 GPH when factoring the head height (how many gallons per hour the pump pumps against the resistance of gravity straight up).
You don't want your return rate to be too high. It makes rigging your sump so much more difficult battling noise, micro bubbles, drain failure, etc. With a nice slow return you will have no problem rigging up a nice refugium below your tank and placing your protein skimmer anywhere you want down there.
You can search and buy overflow kits which are a quarter of a cylinder that you can silicon glue into the corner of your choice where you drill your holes or you could go with a center overflow which would be half a cylinder and you could have your holes drilled in the center.
Have fun man! Setting up a big tank is a challenge, but it is a lot of fun at the same time.