I went ahead and got the 5 tri-x filters and installed them on the spa. I washed out the regular filters and intend to keep them as a backup. Every few months I will wash the tri-x filters in the dishwasher and dry them out. During this time I will use the regular filters just for that day. I asked this on another posting but was unsure of the response: When washing the tri-X filters in the dishwasher it is recommended to use TSP at the same time? I specifically bought TSP to soak my regular filters overnight because it was a non-foaming, degreasing agent.