LFS said flounders would be good to keep the sand clean cuz they always bury themselves. Like everyone else said, make sure you have a deep enough bed and large enough tank, if you do then it'll be cool!
i have or should i say had a flounder. it attacked anything that crossed the sand (ei.snails or crabs)he would also try knocking anything crawling on the walls or l/r.and yes i fed it!!!! it swam like a fish when it was time to eat.they are cool to watch or even find and do require a d.s.b. not c.c.
i hade 2 for a couple of months till they jumped out. they were peacock flounders. i fould one in my sump and how he got there i have no clue and the other was on the floor. both dead within days of each other. it was most destressing.