My husband and I have had our 55 gallon tank set up for 3 weeks now. Live rock and live sand. In my latest batch of live rock from the local pet store, we have acquired a little crab. I figured he would not make it as our water parameters are not quite right yet. However, this afternoon when I got home from work I saw little "footprints" in the sand and tonight I found him! My question is now that I know he's made it- now 3 days- should we put anything in the tank to feed him? I like the little creature and don't want to lose him if possible!!!