Was wondering if it would be ok to put snails and crabs in my sump. I have a little hair algae growing and would like to put some critters in there to help get rid of the stuff.

How big is your fuge? Many people place small snails and hermits in their fuge for consuming unwanted algae. You could just leave them in your fuge until the algae is gone then move them back to the main tank.

Also you should figure out whats causing the hair algae. It could be a sign of high nitrates, and phosphate could also be an issue. You want to figure out where the nutrients are coming from(bio load, water source, foods) and try to limit them.

I do not have a fuge. This is just a 17 gal sump with live rock in it. I also have my skimmer in it.
I thing my nitrates are still just a little to high. But i am working on getting them lower.
Anyway if it is ok to put snails in the sump i will try a few, guess i can always put them in the main tank if they dont work out.

Did not want to start new thread, so will put this in here as it is on the same subject.
I just put in a hang on back refugium. It has a built in skimmer, but i cant seem to get it working. Can't get the bubbles to work right. I have an air tube installed in front of the intake pump which is how i see most skimmers but not sure how big a powerhead i need. I have a 230 gph on it now. And i am not sure if the air intake tube is properly installed into the small air intake. Can someone get me going in the right direction? Thanks

What type and brand of skimmer is it? So you can't get the skimmer or is the pump not the correct model?

By the way danj don't worry you could have added another post if you liked. That way people who have already looked at this post and decided they weren't much help would have paid more attention.

This is a no name brand from aquatraders. But i looked at a CPR and they are the same so i may have already solved my problem.
Thanks anyway.

Well if you have anymore questions just ask.