75 Gal Overflow Setup HELP

[JunkMan]

I want to setup my 75 gal rectangle tank (48x18x20) for a reef tank. My current tank is a 65 gal with a corner overflow. On this 75 gal I want to drill the tank for the overflow pluming but I have some questions...

1. Where should I put the overflow? (middle, corner, etc.)
2. What size overflow box?
3. What size holes to drill and what size bulkheads?
4. Where and how do I install the return line(s)?

I am open for all suggestions and advice. Thx in advance!!

 

[stunreefer Verified Sponsor]

Check out glass-holes.com. They have kits that contain everything you need along with videos to walk you through installation (very easy, just take your time when drilling). I would use the 700 GPH kit, although you could step up to the 1500 GPH kit for more flow. My office tank is the same dimensions and I have one 1.5" bulkhead through the back that provides plenty of flow. Overflow position is ultimately up to you but I would put towards one corner of the back wall.

 

[Jimbo662]

I've got the same size / dimension tank and it's got an external center overflow. It leaves the entire tank open...here's a pick of the back of the tank.

 

[stunreefer Verified Sponsor]

Here's some light reading to get you thinking outside the basic overflow.

Leaving as much space as possible inside the tank is crucial IMO, Jimbo did a great job with his external above. The glass-holes have incredibly thin profiles (~2") and basic strainers can provide the same to.

 

[kingrl2]

Jimbo, did you build that overflow box? I have a 75 gallon that I am looking to do the same thing with, but I'm not sure my DIY skills are up to it. Got any helpful advice?

 

[JunkMan]

I've got the same size / dimension tank and it's got an external center overflow. It leaves the entire tank open...here's a pick of the back of the tank.

Jimbo, can I get more pics and info about your overflow setup? Also big thanks to everyone.