reef custodians

[Milad]

of course ill add them after i cycle my tank! well now i will anyways...

[ponokareefer]

As others have pointed out, either avoid crabs all together, or only get a couple of smaller hermit crabs. I have a couple of them, but only as something neat to have in the tank, not as a major part of the clean up crew. Also, shrimp can and will steal food from corals. I have some in my tank though, as they just look so awesome, that I can tolerate the stealing.
Snails are one of the best part of a clean up crew in my opinion. Get a good variety, and you should be good to go. The one snail per gallon and a half rule is really high though. I would say maximum for you size of tank should be 50. I only have about 20 in my 125 gallon. Avoid the bumble bee snails though.
Also, a brittle star can do a really good job of cleaning things up. Just avoid the green ones, as they will eat your fish.

[lastlight]

Yes I mistakenly bought a green/serpent star for my first tank and it does very well at hunting. Amazingly fun to feed though.

My shrimp were terrible thieves as well but I plan to have one or maybe 2 again as I love them. I would mash some food onto my hand (cyclopeeze I think or maybe reef roids) and set my hand in the water. They'd climb aboard and go to town. Only downside was they were so well trained that I had to basically carry them around on me when I did and maintenance with my hands in the tank!

[BlueAbyss]

IMO, you should consider snails livestock and try not to overdo it. They depend on algae growth to survive, so you don't want them starving to death.

I have an Emerald Crab and an unidentified nocturnal hitchhiker crab in my 5.5, and while I haven't outright noticed any issues with them (and have seen the hitchhiker eating algae) the growth rate of my zoas isn't very good.