I just purchased a house that has an above-ground spa. By the jets/air buttons, it says "Charisma Spas," however I can find no model number. The pump and heater assembly (A Hydro-Quip model) are located on one side of the spa with an access door in the wood housing. The filter is located on the other side of the spa, under a strainer basket. When I first moved in, there was an old, dirty "Type A" filter cartridge sitting outside of the spa. It is the exact type you can buy at Walmart, nothing special. I went to Leslie's Pool Supply to buy a new one, and the employee there told me this was too small for a hot tub. I returned home, and tried to access the filter casing. There is NO top access. If I remove the basket, I can put the A cartridge in sideways into the square that leads to the basket, then turn the cartridge 90 degrees to fall into the cylinder-shaped casing. However I felt around with my hands, and there is indeed plenty of room around the A cartridge - I have no clue how "snug" it should be in there. I went to Walmart, bought a larger "B" cartridge, as it seemed like the right diameter and height. However, it was impossible to get into the casing, as it was too large to turn 90 degrees. I gave up and went back to the A style, which I am not sure is going to filter correctly.
I have spent HOURS trying to find out info about Charisma Spas - their website is no longer running, and I can't find any manuals or anything. I'm hoping someone has a good idea on how to a)find out what model I have b)know where I can get a manual c)replace the filter cartridges with no top access. Everything I read online about replacing cartridges just says "Refer to your owner's manual if you are unsure how to remove the cartridge." Sigh.