So, I’m setting up a new 55 gallon saltwater aquarium for fish, not corals or reef. I had no idea of all the cost involved, but now I do. I built my own stand and got a good deal on the aquarium at Petco. I live in Arizona so the water is terrible, had to buy a RODI system which I set up in my laundry room. I’ll be putting live sand and life rock to start out. I was told that I did not need a heater as these tropical fish are used to colder water. Is that true? I know I need to keep the temperature Between 76 and 82°F. Can this be done without a heater? Another question I have, how long should I let my tank cycle with the live sand before introducing fish? Any other helpful comments Would be appreciated. Eric