CPR CS90 Overflow Box location?

My old tank can not be drilled, so over flow box it is. The one I had was to large so got a CS90 with the Toms Aqua lifter pump.

Thing is my tank had chambers in the corners with power heads, and under gravel all built in. No way to remove it without destroying the tank.
So wonder if putting the overflow box next to the tank center divider would be ok? And the return right next to the chamber on the other side?
I have 12" from the Chamber to the glass center. The overflow box 8" wide, would be from glass chamber and leave 4" between. And would put the Return right next to the other one next to the grate
Not sure at this pointy if powerheads would be pulling water up threw undergravel or reversed to push up? Opinions on that?

 

Those vertical risers for the under-gravel filter should pop right out. That should give you more space.

 

I think it would brake the tank. the glass is epoxied onto the tank. It was set up as an undergravel system. the center glass is also support for the tank

http://i234.photobucket.com/albums/ee87/fast340six/Tank/Tank-7_zps5b3322b8.jpg
http://i234.photobucket.com/albums/ee87/fast340six/Tank/Tank-5_zpsfa477853.jpg

 

Hmmm those look like overflow boxes to me. Try this inside those boxes:

HOW TO: DIY Aquarium Overflow - YouTube

How it works:
http://www.youtube.com/watch?v=7DFk4bnIxEg

 

Did you buy the tank used like that? If so, make sure it's clean under the plenum. Gunk will build up there if the tank was overstocked, overfed, and/or not properly maintained, and if that's the case, you're already in trouble before you even get it wet since the UGF can't be removed.

Personally, I prefer the old UGF, and I run mine in normal direction. Light fish stocking, a large CuC and frequent vacuuming will keep it running trouble-free.

As for your HOB overflow and return positions, that will work just fine.

 

WHAT is that in that tank? Carpeting?

 

Long ago i looked at doing just that. My good friend is a plumber and I know some about it.
The pipe in that Chamber is glued in and can not be removed it is just s stand pipe that is glued to a fitting. That fitting is in a bed of some epoxy that is attached to the built in place under gravel.
Ideal would be drill under that pipe and have it be a drain. But the bottom can not be drilled. So only option is hang on over flow box on back.
I have a box but was just to large and would have placed the tank far from the wall. So got a slimmer one from CPR
Just wonder how well it will work with the placement issues I have for it
The center of the 8" wide CPR Box will be 25" from the return hose

 

Sorry it took so long to check the thread.
No I bough this tank in 1990 as a new Oceanic and the Locak Fish store added the under gravel, the boxes, and put crushed coral / rock to the rear glass with some epoxy.
I ran it for years and years with just the under gravel.
Started with 3-4 Damsels to cycle the tank and did water changes as needed. And bulit up stock just fish only.
Ay one time had a large Grouper {spotted} a porcupine puffer, Yellow tang, Niger Trigger, and brite blue Damsel
The under side under the under grate is clean, so is under the plenum. you can see it from the under side well.
My guess was the glass was sanded, and some type of Polyester Resin was poured on. Then the same crushed coral like used for the under gravel was added while still wet.
I remember running it with plain water and doing a fill drain 2-3 times before filling with salt and water when it was new to make sure it was not going to mess with the fish.
I built the stand and hood in mid late 1990