Building a refugium with Exsisting equipment

Right now I have in operation a 10 gallon Aquarium that is being used as a sump for my 46 gallon bow. This 10 gallon is partitioned in half and half is being used for the water intake, with bio balls, and filter material. The other half is used for the return pump. Can i take this glass tank, and have a few round holes drilled in the side of the return side? My goal is to purchase a 20 gallon aquarium and place the 10 gallon in there, and move my return pump over to the 20 gallon side and use the 10 gallon side as a refugium with live sand and cheatao. Esentially placing a 10 gallon aquarium inside a 20 gallon aquarium. Tell me what you think

 

Why not just partition the 20 gal? My sump is a 20 gal long and I have it partitioned into 3 sections. The drain with my skimmer, the refugium and the return. Work perfect.

 

Because i allready have a 10 gallon, and It is ready to go, plus i dont like to mess with getting glass cut and silicone it into position, i was thinking that this would be a cost effective way to go.

 

I would go with just using the 20g long divided into sections. And even though I've never done it, I've heard drilling a 10g is nearly impossible.

 

I guess you could try drilling it and if it doesnt work out then you dont have an option left but to use the 20.