I have this large tank it is 85 gallons i have been working on for quit some time know. Money issues.:-| I just don't no where to start i have over 100 lbs of rock and a pf500 tetratec filter. i beleave the rock is for freshwater. Does that matter? or can it still be used for salt water. i was thinking of making it a freshwater but other people say i should make it into a saltwater tank. The only thing that is keeping me from making a saltwater is the money. I am just thinking to much. I don't no thanks for all the advice. Bonnen13