Where to drill for returns.

[masssnapz]

So I finally made the plunge and ordered a threejole overflow kit from glassholes to get rid of my HOB eshopps. I ordered 2 x 3/4 inch returns to go with the kit and have no idea where the best place to drill for them would be, right now I have a single return over the top on the right hand back corner. Should I keep the same idea and drill there or is there a better option ?

Tank is a 90g aga standard 48x18x24 sps dominant reef.

 

[Smo]

I have a 36" wide 65 gallon tank that I drilled two 3/4" returns on the back glass. The holes are 6" from the sides and about 1 1/2" from the top edge. I wanted to minimize the amount of water draining back to the sump with the return pump off. As a rule of thumb you also want at least a hole diameter away from any edges to prevent cracks.

 

[masssnapz]

I have a 36" wide 65 gallon tank that I drilled two 3/4" returns on the back glass. The holes are 6" from the sides and about 1 1/2" from the top edge. I wanted to minimize the amount of water draining back to the sump with the return pump off. As a rule of thumb you also want at least a hole diameter away from any edges to prevent cracks.

Ok so that seems to be in line with what I was imagining in my head.

 

[Smo]

Should work well for your tank. In my case two returns was overkill but I considered it an "engineering mockup" for a larger tank one day.

 

[miPapareef]

Good luck with the build.

Here's an example of a 75 gallon tank, single 3/4" return 8" from side and 2" from edge of the hole to the top of the glass.

 

[Seyoz]

I would do same measurement as left side, gonna bug you if of a mm, believe me you'll see it...If your doing PVC lil tricky plumbing for return, but beautiful done right....

Lots of people just run hose for returns with Y part from LFS..
Quick and easy to plumbing.