sea star

what type of sea star would be good for a 20g high tank, if any?

 

Unfortunately, the majority of sea stars are predators with a very select diet, preying on only one or a small group of corals or inverts. Many may claim "success" after just a few months, but some stars can take as long as 2 years to finally succumb to starvation in captivity. Most also grow too large for a 20g, if they do survive long enough.

That said, brittle and serpent stars tend to do well, although larger species may need target-feeding periodically to prevent them from becoming opportunistic.

 

I agree 100% with Mr.Bill. If you must have a star fish try a brittle. If you want something hardy and not reef safe a Chocolate Chip (Protoreaster nodosus), will get large and will eat some corals and clams though, but it will take supplemental feedings well.

This is another I have kept a few times for a couple years each time. This star will require an area of the glass that is allowed to accumulate film algae/biofilm. It will not survive long in a clean tank with no area to graze.
Red Sea Star

 

k thanks that info helps i will just probly hold off till i put together a bigger tank

 

That's fine, just study your desired species on sites other than online vendors to determine it's true full size and dietary needs. Many (if not most or all) sellers advertise the majority of sea stars as algae grazers or detritivores.