Ozone man, ozone. Not only keeps fish in perfect shape* but keeps the water crystal clear.
*I don't have an MBA but I did stay at a holiday inn last night
Alright listen I am sure all the advice everyone is giving here is spot on but truthfully you should be able to have crystal clear water with next to nothing. I have always had crystal clear water with just a filter sock. Its more likely something is wrong with your setup ie not enough flow and turnover. The products everyone is speaking of are awesome and can make your tank brilliant but you should be able to enjoy some beautiful water without them
What equipment is needed to run ozone?