55 gallon tank

Question
I have a 55 gallon salt water tank in my office waiting room.  I have had the tank for 8 years with numerous service providers who have all disappointed me miserably.  I have live rock, live coral, and 7 fish.  We have a protein skimmer and a chiller.  The tank has at times thrived but recently we have minimal red algae and possibly a phosphate problem.  Now a potentially new service provider is suggesting that we change to a fresh water tank.  No one in the office is an expert on either but we enjoy the tank and do our best to assist in between servicing.  I don't want to fall for another sales pitch and I don't know what to do and would appreciate your insight.

Answer
well usually red algae blooms are caused by old lights, as the tube ages its spectrum shifts more into the red zone and this type of algae thrives under those lighting conditions. simply change the tubes for new ones and do a 24 hour black out on the tank, this will reduce your algae and also keep it at bay with the new tubes. your service provider should be able to get these for you, i recomend you get 10,000kelvin rating white tubes suplimented with actinics for extra colour.

what was your last phosphate reading? there is a product on the market called phosban, its filter media that absorbs phosphates and should be replaced monthly. again your service provider should know about this stuff.