When you mention 'SWCG life," are you referring to the life of the cell or the complete system? Can you also give me some feedback on a Hayward 150 sqft cartridge filter with a 2 speed pump? Do the benefits of paying the extra $$$ for a 2 speed pump outweigh getting a 1 speed pump? If so, is it advisable to leave the low speed pump on 24/7 vs set to high speed for 8 hours/day?