Salt Water pools generate chlorine using a device called a salt cell. When the salt cell stops working, no chlorine is generated. Without chlorine in your pool, algae can take over quickly. Pool algae can appear as green, yellow (mustard) and black. Green algae can usually be killed quickly (when treated early) by shocking the pool, brushing the entire pool and running the filter for 24hrs. Yellow algae can be more difficult to kill and will require an algaecide and vigorous brushing. A high chlorine level must be maintained when killing yellow algae or else it will begin to bloom again and the shocking process will have to be repeated. Black algae can be extremely difficult to kill even when shocking or using an algaecide. Once it's roots get into the plaster, you may never completely rid the pool of black algae. We were recently contacted to address a yellow and black algae problem due to a salt cell failure. The client shocked the pool and treated it with an algaecide, but the algae remained. Check out our results in 24hrs. If you're not getting the results your desire, call JB Grande at 850-625-9750 for our Green to Clean service.