Drilling the back of your tank


New member
I havea 125g that I just purchased w/ Tank, Stand, and canopy for $225.00, I want to drill it, but the bottom is tempered....

Want to see some pics of back drilled tanks, please include specs, as to what size holes you used for what purpose..

I am looking for somehting simple, I will be running a sump w/ fuge underneath...



New member
Pic of my setup

Pic of my setup

Here is what the setup looks like:
72" X 18" X 24"



New member
did this for 75g

did this for 75g

here are some pic's of what i did this last weekend
used a 2 3/8 diamond bit plumers putty to make a dam filled with water drilled slow the bulkhead is sk 80 1 1/4.
hope this helps


New member
My understanding is that you'll get 500 GPH per half inch of hole. This does not account for flow loss if you are using a stand pipe or the like. I use a 1.5 inch hole.

Make sure that the hole you drill is compatible with common size fittings as well. You're going to be screwed if you use a 2.5 inch hole or somthing like that.

This are some pics of my 90:





Premium Member
I have an AGA 120 gallon. I drilled for two 2" bulkheads in the back, between the overflows. these feed my closed loop. (I also drilled several holes in my 90 gallon sump) Lots of pictures can be found by clicking my litle red house.


In Memoriam
No pictures but I drilled two holes in my 200g reef, a large return hole for an external sump in a 75g below the 200 and two holes in a 56 for a fuge. It was super easy as long as you take it slow and use the diamond drill bits at home depot