To chemically clean the grids/ nest:
1) Have a bucket/container large enough to hold the entire assembly - A large plastic garbage can works well.
2) #1 Add some TSP (tri-sodium-phosphate) to the water or some electric dishwasher detergent to the water and soak the grids for at least 3 hours - this will "de-grease" the membranes and is the first step in cleaning them, rinse with hose and get ready for step 3.
3) Dump the container, refill with water and add muriatic acid to the water so that you have a 10:1 water:acid mixture and soak the grids for at least another 3 hours, this will clean any calcium off of the grids. Rinse grids again and reinstall them in the filter.
4) Now, run pump and bleed off the air from the filter and add 100% of the DE the filter calls for.