Landscaping: What type of lawn fertilizer is recommended and how does it affect the lakes?

All homeowners are to use phosphate free lawn fertilizer.   Lake water testing showed there was twice as much phosphate leaving our large lake than coming into our small lake from the Cherry Hills subdivision. This increased level makes it more difficult to control algae and plant growth in our lakes and requires more chemicals to be applied.  Phosphate free fertilizers are available through the professional lawn chemical companies, hardware stores and garden centers.