I have a 7 year old Aquapure 1400 system, the cell was replaced 4 years ago. The cell needs replacing again and I'm wondering if I should replace an older SWG part (the cell) or replace the entire SWG system with (hopefully) newer technology?? If the answer is yes, which system would you suggest I upgrade to for a 22,000 gallon pool? Is the new AquaPure EI system adequate as a replacement? I have very hard water and the salt cell cakes very quickly so I want something where the cell is easy to clean. Any help is greatly appreciated.