well i was going to buy the 75 then the guy flaked so i bought two tanks. a 60 and a 40 and i was thinking about puttin them in the 40 but its a mix of crushed coral and sand in there and bout 1/2 in thick. my 60 is completly stocked with sand. and whenever im putting them in i dont want anthing to eat the shrimp or else all i have is the goby with no shrimp then its a 35 dollar lunch. so... what are yalls ideas on that? thanks to everyone who posted and helped