Waste....I appreciate the info about disassembling the top of the filter further. I will do that before I hook it up this spring, and when I clean it again in the fall. Thanks! Naturally, the pool store didn't tell me how to do that. They told me to just pull off the whole top, as I posted above.

Regarding the oils....what is TSP? I have seen a laundry detergent solution recommended instead of using acid. I think it was about 1 cup of detergent to 5 gallons of water. I used that in prior years, but it didn't work well enough on it's own this past season. Last fall I soaked it in the detergent solution, hosed it off, then soaked it in the acid solution. That worked quite well. I thought the 1:1 ratio was way too strong as well, I used more like 1:10!