Aiptasia:
-I think peppermints are the only solution to these.
Bad things have been said about these, it really is hit or miss. They will do the job, but many people complain (including me) that they attack newly added, or even corals that have been in the tank. But, I don't think peppermints will attack SPS, they have only attacked (on my record) LPS, Sessile Inverts, Polyps, and SOME other soft corals.
-There are also some nudibranchs that will eat them but these are rare and hard to come across.
Algae:
-Emerald Crabs are good for getting algae.
-Hermit Crabs, Its not hit or miss, it depends on what kind you buy. The small ones (usually not over 1") that come in color morphs from blue to red to brown are the reef safe guys and won't hurt anything. And the blue knuckled ones and SOME other hermits are completely reef safe and are an essential component to a reef.
-Turbo Snails, Ceriths, Abalones, etc. are excellent for taking care of filmy algae on glass.
-Sea Hares are the best for large algae problems, but must be fed when no more food is present or they will quickly starve. And pumps/anything they can be sucked into should be covered.
Other:
-Nassarius snails are terrific, and a great part of your clean-up crew. They will eat dead/decaying things and sometimes leftover food
-Serpent Stars-same as above^
-Cleaner shrimp (skunk cleaner, fire etc) are probably the best thing you can have as your cleanup crew. They will eat ANYTHING, even fish poop. And they are beautiful additions to your tank.
Hope this helps
