Hello I'm new to this website I have a 55 gallon fish tank that I'm going to try saltwater it's my first time trying saltwater fish tank. I have an ehemi Pro 4 + 600 canister filter also I have a digital aquatop digital aquarium heater 200w with a hydro wave pump. My tank is 48 long 12 1/2 wide by 20in deep. I have no Rock no sand no light is there any other piece that I should buy for an saltwater aquarium. Also what is a good recommendation for a light. I'm also on low-income budget so everything will take me couple of months to get. Thank you for your time and have a nice day.