Refugium

[ErinCahir]

So I've been doing a lot of reading on the site and I think we want to do a refugium. Why I didn't know about this before is beyond me. So we've got a 150gal with sump filtration. I was thinking maybe a 20gal refuge? I know that it's recommended to have 20% of the tank capacity, but I just don't think I'll be able to fit anything bigger than a 20 tall.
So, educate me a little bit. (And forgive me if my questions sound a little silly).
I figure we'll get some chaeto and some live sand... should we put live rock down there? Or any rock? And I assume we'll need some shrimp (we don't have any in the big tank, I'm a little paranoid about it because we have a Niger Trigger, and I think he'll eat 'em).
I know the flow needs to be really low in the refuge, so I was thinking two small pumps... one to get the water from the sump to the refuge, the other to get in back to the sump. Is this a silly way to do it?
Thanks!

 

[Bifferwine]

You can use live rock rubble in the fuge -- it will be a good place for bacteria to colonize, and it will provide a place for pods to live.

I'm confused about shrimp... Why do you need shrimp? That is unrelated to a refugium.

If you use two small pumps, you risk overflowing or draining the refugium. They would have to be perfectly matched to each other -- and that's not going to happen.

Instead, you could either build the refugium into your existing sump (section off part of it will plexiglass baffles), or make your refugium out of a rubbermade tub, bucket or container. If you raise the tub slightly higher than the sump (mine is on cinderblocks), then you can put a hole in the side of the bucket and plumb a piece of PVC into the side of it. Then have a small pump (I use a MaxiJet) bringing water to the fuge, and it flows out the hole in the side and back into the sump via gravity.

 

[ErinCahir]

I was a little confused about the shrimp. I was thinking tank cleaning, unrelated to the fuge. Thanks!