Never it is way too small for a starfish a 50 gal tank is good tho
Cause there is algae that grows on the side of the tank, and that's what the starfish eat.
No, Starfish aren't supposed to be in a reef aquarium AT ALL especially in a nano aquarium such as in your case.
None
White spots on a starfish usually indicate illness. If the salinity in your tank has changed, it can cause the starfish to become ill and may even be fatal.
Most starfish graze on film algae, and tend to go to where there are high quantities of algae. Chances are your tank has lights, and the algae will grow stronger closer to the light. The other reason is the starfish could be getting bullied by other tank mates, so it's just getting a break from the others. Look at your tank at night with a torch, the starfish should be down the bottom grazing while the other fish sleep.
About the size of your face!
no they do not A good estimate would be 5% of tank size.
Watch what happens outside the tank, read the manual, and comfort Nemo after the failed escape.
Yes, as long as you take proper care of them :)
Well, there are lots of different types of starfish and that means that they can't all be the same size. :)
The original tank was a 20 gallon gas tank. These tanks can be easily found and replaced by a good mechanic.