I've just added one a cpl weeks ago. He took a while before he came out but now he just started to crawl out during feedings so I'm happy with that. I've also had Ferdinand my cave goby for a while that moves the sand around but thats only in his man cave lol. It might be my lighting that I need to adjust bc everyday I turn the sand over and then the next day like clock work I can see tiny little algae growing again. Its an ongoing battle but I will be victorious one day.Florida Fighting Conchs are amazing! (Sea Hares, too— but seem to croak after a year.)