How to remove a big crab?

[ram6519]

I put in a couple of Peppermint shrimp to headoff some Aiptasi and I have not seen anything of them in over 2 weeks. A couple of nights ago while looking for them with a flashlight I noticed a big crab hiding in my live rock. We have had this LR for 2 months and this is the first time we have ever seen him. He is peach color and one of his claws is larger than the other. I can't get a picture of him because he won't come out of the rock. Would this crab have eaten my shrimp? How to get this crab out? Will a freshwater dip in RO water make him come out without damaging my LR?
Please help save future Peppermint shrimp.....

 

[Kiko]

I had a couple of small crabs in my tank a while back. I got rid of them by putting some pieces of shrimp in my net, and holding the net in the water above the live rock. The crabs grabbed the net and went after the shrimp.

All I had to do was lift the net out of the tank - the crabs were clinging to it - and brought the crabs back down to the beach where I found the live rock they came off of. They just ran down the beach and into the ocean.

I live in Hawaii, and these were local crabs; all of my live rock was found after a bunch of storms washed a lot of stuff up on the beach a couple of years ago. You are allowed to take 1 gal buckets of stuff off the beach at a time. Some of the rock I found actually had mushroom polyps on it, which later spread a bit through my tank.

 

[Kiko]

Oh yeah, I forgot to mention. I had a horrible aptasia problem - a complete take over. They were everywhere. Every time I would clean the glass, I would knock a few loose, and they would multiply.

I bought a Racoon Butterflyfish 2 weeks ago and it has eaten 100% of the aptasias! They are all gone. Now this fish is eating flake food.

 

[Doug01]

Easiest trick I have found for crabs. Take a kitchen glass and put some Brine shirmp in the bottom of it and lean it up against his rock. Crab goes in and can't get out. Worked like a charm for me!