hey all i have 2 fishtanks both tropical and both empty.. one of them im gonig to be keeping as a tropical tank. the second tank i am thinking of using as a marine tank... it is 3ft long and 1 ft high. now how much money roughly would it cost to convert this tank to a marine tank.. without any fish or anything. like the lighting, heating, filter etc etc. i have never kept marine fish before so ideally i just want to set the tank up as a marine tank and leave it a few weeks and keep checking the water to make sure i have it spot on then introduce some coral etc to it and lasty the fish. any advice is appriciated. i have the heater, filter etc for the tropical tank.. but i cant use it in a marine tank can i ?