We recommend heat pumps because of their high efficiency. They look like an air conditioner, and actually take the heat out of the air and put it in the pool. Heat pumps work when solar won't, and don't require panels on your roof. Avoid propane heaters due to their very high operating costs.
Salt chlorine generators make chlorine from salt. They allow a lower level of chlorine in your pool, and result in water with a soothing, smooth and silky feel that doesn't dry your skin out. Salt systems are catching on rapidly; most new pools are now built with them. We can update your pool to take advantage of this great new technology.