not to be a negative nancy. but think about this. if this fish's NATURAL diet consists of eating external parasites off of fish, it will have a high dietary requirement. why? think about a parasite, what does it eat? it eats the vitamin rich, fatty tissue of a fish A LOT. every bite that cleaner wrasse would take in the wild would be calorie packed! now think of a brine shrimp, it eats much less nutrients, less often. on top of that, it can also burn the food that it took in, meaning not all brine shrimp are created equal!
think of it this way, if you have Michael phelps over as a house guest, is he going to do very well if you feed him only three meals a day? his metabolism is used to seven.
and ich is a sub dermal disease, meaning there isnt a huge deal of nutrients for a CW even when he is constantly picking on a ich infested tang. in the wild a cleaner wrasse has access to the JUICY parasites.
as i have heard from quite a few retailers who refuse to sell them because they are an almost guaranteed death, even of it isnt immediate. that and the fish is an essential part of a reef ecosystem, they are very beneficial and it doesnt help to take out of the breeding pool, even of it survives....
go cleaner shrimp!