Pump serving as both return/overflow?

[Enoplus]

Could I use a single pump to simultaneously pull water into a sump and return it back into the main tank? This is basically how canister filters work right? Or is this a stupid idea? I just want extra water volume and somewhere to put equipment without drilling or anything else. I don't need any baffles or chambers or whatever.

 

[Cichlid Dad]

Could I use a single pump to simultaneously pull water into a sump and return it back into the main tank? This is basically how canister filters work right? Or is this a stupid idea? I just want extra water volume and somewhere to put equipment without drilling or anything else. I don't need any baffles or chambers or whatever.

How is the water over flowing from the tank to the sump?

 

[Enoplus]

How is the water over flowing from the tank to the sump?

In my head the pump would serve as both the "overflow" and also the return but I just realized that this would accomplish nothing since it would just be circulating water through the pump and its tubing.

 

[Cichlid Dad]

In my head the pump would serve as both the "overflow" and also the return but I just realized that this would accomplish nothing since it would just be circulating water through the pump and its tubing.

You have to have a overflow and pump water from the sump to tank. You can accomplish that without drilling.