If you want your cleaner wrasse to survive (I am only saying this because you already have it) you have to get it to eat. The thing to remember about cleaner wrasses is they do eat but they are very "passive" and have small mouths.

The one I have that eats flake food will never eat flakes from the surface of the water. Sometimes they don't eat the flakes on their first pass, they have to study it first. Then they come back and eat it. (They also only eat the flakes that have the fish meal not the ones with algae in it).

If you have voracious eaters in your tank your little cleaner wrasse will starve because it "does not eat".

The way I had mine "learn" to eat was by putting vitamin B6 in the water then let it get spread out into the entire tank. Give the vitamin a few minutes to work. Then with other fish in the tank that eat put the food in the tank. The cleaner wrasse will eat after that.

Mine also likes brine shrimp, and finely cut shrimp (very tiny pieces as they have teeny tiny mouths).

My little cleaner wrasse also "hunts" for piecesof food that may have reached the bottom and eats those.

After having done reseach on cleaner wrasses I have one recommendation to make on cleaner wrasses:

DO NOT BUY CLEANER WRASSES OR SUPPORT STORES THAT SELL THEM!!!

If you buy a cleaner wrasse then all the fish that were being cleaned by the cleaner wrasse in the wild will die horribly painful deaths. How does this affect you?

The prices of the other fish you buy will skyrocket due to decreased availability of fish in the wild. Corals will also die due to the balance found in nature and the valuable cleaning provided by certain fish. This will also cause your neighbors to spontaneously combust and the resulting fire will burn your house down. All this because YOU bought a cleaner wrasse.