im going to buy a small 10 gallon tank to house 2 or 3 clownfish. i was wondering if i could just use a freshwater filtration system to filter the saltwater. im going to use live sand and put tap water in the tank and then mix it with instant ocean salt. but again, im getting live sand, coral and 2 or 3 clownfish. is the filter ok? and im getting a bubbler and hydrometer. is that it?