Refugium: over or under? discuss

I am in the process of planning my 45G display tank which will ultimately house some corals. I have experience keeping FOWLR, but this will be my first attempt at corals.

I have read alot about refugiums and definately plan on this being a part of the filtration system. I have read some books that tout the benefits of a refugium being "above" your tank in the circulation cycle, however most photos or disucssion I have seen here the refugiums are below.

Any advice on success or tips would be great. I only want to set this up once. I don't have space to put the refugium in another room behind a wall, so that is not an option.

Thanks!

 

well if it's below you are going to need an overflow and a pump to return the water, usually people incorporate this into their sump so they can have their skimmer and reactors down their too.

with an above you only need one pump because the return is just a pipe coming back to the tank.

I would go with an above if you are going to be using a HOB skimmer or HOB reactor

 

You would only need one pump either way.
If you have it above the pump would be in the DT, the fuge would then need an overflow or to be drilled.
with it below,the pump would be in the fuge with the tank being drilled.

the choice would depend on space and if you want it hidden or displayed.
the only benefit i can think of is that maybe the pods would move to the DT easier b/c they do't have to go through the pump.
what benefits did u read about?