Is it possible to have a cheap Reed tank that is 20 gallon? This includes RODI water system, lights, corals, fish, , etc. I have a 20 gallon tank with a rim and a penguin marineland filter that is currently running a freshwater tank, so my two questions are, can someone tell me if it is possible to make a cheap reef tank? If so what do I need to buy to make it cheap? (Budget is 300 dollars for everything). Second question is how do I transfer freshwater to saltwater? Do I have to recycle, etc. Pls help.