New to saltwater

[heatherjh13]

Hi I have a 20 gallon saltwater tank, with one snow onyx clownfish one maroon clownfish one damsel. I am having a problem with pink stuff in my sand. I am wonder what snails, hermit crab ect. i could add to help clean the tank and how many. Also my maroon clownfish fin is nibbled off, the damsel and it seem to stay close but the snow clownfish keeps its distance any tips?

 

[JumboShrimp]

Sorry to say, that particular choice of three fish is probably not ideal for a 20 gallon. There could be more aggression to come.

Can you post a photo of your tank, so we can see if it's cyanobacteria?

 

[Tahoe61]

Hi and Welcome to R2R.

Sounds like Cyanobacteria as stated above.
Clowns are Damsels, an aggressive reef fish that will not tolerate other Damsel types in small tanks unless it's a pair.