How big of a refugium?

[MRDHJ1]

O.k. heres the question. How big of a refugium should I have on my 125.

 

[jkreefer]

Are you doing a fuge/sump?

 

[MRDHJ1]

no just the fuge I already have the sump.

 

[jkreefer]

20-30 gallon would be fine if you have the room