hey bill, u can use sand and i would. use any kind u want. my cichlids loved it! they would sift it through their gills. i never worried about any ammonia or anything with my FW. just put it in and let it settle before u turn on ur filters or put fish in! i used sand that was like aragonite from the beach and just boiled it. it looked really cool. are u askin what equip. u need for a 50? u can do very simple or as ccrazy as SW. i would do an AC110 and a heater. but u could do powerheads, air stones what ever u want its just not needed.