I have a 120 gallon acrylic fish tank, about a year a ago the heater split and poisioned the tank. Everything has been long dead. My question is, after you take out the rocks and sand, there is still probably 100 gallons of water. What would be the best way to go about breaking everything down cleaning all the algae out and fixing the scratches before restarting the system? Also what would be a cost-effective way of getting that much salt water. I live about an hour from the ocean, but being near Los Angeles I don't know how clean that water is? Any thoughts?