Relocating drain hole on display tank?

Hi Everyone,

I'm in the thought process of changing my 112 gallon acrylic african cichlid tank to saltwater. currently it has a build-in overflow with a drain at the bottom which flows to a pump that goes to a sump which is above the display tank (reason: awkward location, etc) and the return is gravity feed to the display.

I plan on changing out the sump tank to a larger capacity and due to limited space above the current location (for a protein skimmer), i want switch it to a "traditional" system (display- gravity fed to sump- pumped to display). In order to do this (because of awkward location, etc) i can't have the sump 100% below the display. So i need to relocate the displays drain hole to a higher location within the overflow section so it can feed into the sump.

Is it ok to plug the bottom hole and drill a new hole in the side of the tank in the overflow section without compromising the structural integrity? I'm also worried about the lack of water circulation in the overflow section...

Pic of current and the new?:

 

1. Is this a built-in overflow box?

2. Is there plumbing in the overflow compartment of the display tank?


I don't see why there would be any need to relocated the drain.

 

Yes it is safe.just actually did this on a 180g tank afew weeks ago. As for circulation just suck out the bottom during water changes or stick a powerhead in there and you'll b fine.

 

The thought of having a pump on a drain makes me worry...

 

If you have a built-in overflow box, just run with it. When I design our custom setups, they all have the standpipe holes in the tank bottoms inside an overflow box unless I run an external built-in overflow.

If you do want to change where the standpipe(s) is located, make sure you leave a 2" margin from the edge of the tank panel when you drill the hole(s).

 

Just plumb the drain to the other side. You can have the sump pretty far away as long as the pipe is at a slight downward angle, gravity will bring the water across the room if need be. It would be much simpler/safer and cheaper option than re-drilling.

 

Here's a pic. (green-skimmer, red- pump)

The sump is basically level with the display tank so using the bottom drain can't be used.

I've also considered using a overflow box instead of cutting a hole, but that would mean cutting up my lid and i'm not sure if it'll fit with my lights.