Just bought a house with an existing inground plaster pool. It has an older Pentair DE filter, and a non-functioning salt generator. I haven't dealt with DE for decades. After having trouble keeping the chlorine levels up (with liquid chlorine), decided after 2 months to check the filter. Glad I did. It looked like it hasn't been cleaned in a year... I have lot's of questions and look forward to your collective wisdom. Thank you.