sump/refugium

[pipermurphy]

Okay, I am confused on a couple of items. On an earlier post I had I was told to remove the bio-balls from my wet/dry and make it a sump. Done that. Now I have tried looking through old posts and am confused on what is a sump and a refugium? anywhere I can get more info?
Also, on my overflow there are 2 holes one is used to my sump what should the other one be used for?

 

[fishfreek]

If your overflow has two drain lines then they should both go to your sump.

The difference between a sump and refugium is the following.

A refugium usually has sand and some small amount of live rock. Also there is often some macroalgae growing in it and usually its lit either 24x7 or is lit on a reverse photocycle from the main tank.

A sump is simply a storage vessle that holds extra water, skimmers, heaters and any other equipment you want out of the tank.

 

[Anemoneman]

Also, on my overflow there are 2 holes one is used to my sump what should the other one be used for?

One is plumbed to the sump. The other is for the return line (keeps all plumbing out of sight).

 

[fishfreek]

Guess I should have asked if this was an internal overflow or a hang on. I have a hang on with dual drains.

 

[Anemoneman]

Point taken. Depends if your overflow is internal or external.