I had my pool(13k gals IG) re-done, new plaster, tile and equipment about 15 months ago, after about 6 months, I noticed the IC-40 SWG started putting out less chlorine, so had to raise the % from 20 to 40 to 60 to 80 then it basically quit putting out chlorine, I then determined the SWG was caked with scales, no wonder it quit, so after conferring with a pool expert, he said to add the Scale-free liquid route, I did and it did not seem to help much, maybe added 2-3 weeks before I had to clean again(which is now every 2 1/2 months)........by the way, after cleaning in a bucket and getting the plates clean and clear, the SWG puts out great at 20% for about 2 months.........been keeping the ph below 7.8( it is tough to do that) and keeping the alkalinity in the 120-150 range(also hard to do)..........using AquaChek pro strips.......any suggestions would help, cleaning this thing takes over an hour and I have to cut long popsicle-like sticks to assist in loosening the scale from between the plates, acid mix doesn't get it all.