My spa has 2 different threaded holes for the filter cartridges. I can only find new filters that come with one type of threaded adapters atttached. My old adapter won’t really fit properly to the new cartridge even after some whittling to make the slots deeper. Anyone have any suggestions or know if there are adapters to make the narrower-threaded adapter fit the hole intended for the bigger adapter? For reference the filters are PSG27.5. Attached photo of the two different adapters. The narrower one on the left with fewer threads is the what came on the new filters and fits perfect in one of the two spots in my spa. Thanks!
