my uncle recently gave me and my boyfriend his old saltwater tank and filteration system which i think is a premier wet/dry trickle filter with prefilter boxes. it has all the works, bio balls and everything. i was just wonder, since it was originally a saltwater system and tank and was used for salt water, can i just clean out the bio balls and system and use it for freshwater? I’m no stranger to freshwater just saltwater, any advice or helpful answers would be strongly appreciated.