I would point out that I am also a marine biologist, and in fact one that specializes in echinoderms (yes, brittlestars specifically, but you can't have everything
).
I am not saying this store is bad, not at all...most don't understand the needs of these stars.
This species of Fromia star does not get large, that is true. That has nothing to do with its diet and needs. If your star is alive in 18 months, than
. Unfortunately, most don't live that long...though many think they are short lived (this is untrue). They take up to a year - 18 months to starve. What we do know is that success is HIGHLY correlated with the amount of LR and maturity of the tank. So I will always tell people to go with larger, mature tanks...because I am not in this to sell these animals. I was for awhile, and I had a moral dilemma with it, so I quit.
These stars do not eat "algae" as we consider it (nuisance, macro). If they ate algae, they could live in just about any tank, yet they do not. Their diet is basically unknown, and rarely do they take to spot feeding (though I strongly recommend trying)
A quote from invertebrate zoologist Dr. Ron Shimek:
Their small size recommends them to hobbyists, and if their diets were known, they would likely be good aquarium animals. Individuals of Fromia species are found on both reef rubble and reefs. Some Fromia are considered to be sponge and tunicate predators, but the diets of most are not known. Fromia species appear to do well for awhile in established aquaria, presumably as there may be a source of sponges and small sessile animals for them to eat. They seldom persist much more than a year or so, before they "run out of gas and sputter to a stop."
Indeed, if you look on Bob Fenner's site, you see that most of these Fromia stars are in some state of peril based on the questions. All too often true.
Now it may work just fine, but I will not tell people it will, simply because that is not a true statement. Most of these stars that I see are dying at the LFS of acclimation shock, and many more will die within 18 months. I never encourage claims of success before this time period.
Again, please note I am NOT trying to sell anything. When two opinions differ, this is the first thing I would consider - the financial gain. The second is experience. And the third is, frankly, which is more conservative.
I am merely trying to encourage a great deal of hesitation before purchasing such a star, because indeed most do not survive long term. Most showing signs of disintegration are doomed, and the only chance to recover is with pristine water conditions (this is why I ask for tank parameters).