i too plan on catching my peppermints and keeping them in the refrigium until they are needed to combat aptasia. i've heard you can make a homemade trap, haven't tried it yet but here's how:
- take an empty 2 liter coke bottle, wash thoroughly removing all labels, gunk, etc.
-cut the top off the bottle 1" before the cylinder starts to taper in. then cut the very top (where the cap goes) so you have a 1" - 2" dia hole (depending on what you're trying to catch).
-silicone the collar piece back onto the bottle outside-in. you now have a trap of sorts that allows critters to get in, and since the opening is an inverted collar it's more difficuly for them to find their way out.
-fully submerse the trap in the front of your tank with a few pieces of clam or shrimp inside. best to do in the evening and let sit overnight.
-lay low for a while and see what you get!
again, i haven't tried this yet so i'm not sure how well it works - anybody else care to elaborate?
cheers