How Is Sump Size Determined?
 

I have a question on sump size. How do you determine the proper size for your set-up? I'm thinking about doing a 55 gallon reef tank just because I have one I'm using for fresh water right now. What would be the correct sump size for this set-up?

There is no correct size.

Lot of people will just pick the biggest tank that will find into their stand. Of course you do want to pick one that will be big enough for what you'll put in it so think of the equipment your planning (in-sump skimmer, HOB, internal or external pump) do you want a refugium, etc.

A sump is just used to provide increased water volume for your system (things can go downhill a lot quicker with less water) as well as a place to "hide" things such as heaters, skimmers etc that you wouldn't want to have detracting from the display tank.

While I'm not aware of any calculations for "correct" sump size, it doesn't mean there isn't one out there. I just got the biggest one that would fit in my stand :biggrin:

The bigger the better.
Get the biggest you can afford and have room for.

What is a refugium?

Simply a area without predation (a refuge).

I can be a separate tank, as part of a sump or even a area of the display partitioned off. There's different types though most seem to combine or have for growing macro (nutrient export) and a area for pods that will make it (hopefully) back to the display.