Your directions state:
For all spa cartridges and elements used in swimming pools where perspiration, suntan lotions, and other oils are present, soak the element for at least one hour (overnight is most effective) in (1) a commercial filter cleaner; or (2) one cup trisodium phosphate (TSP) to five gallons water; or (3) one cup dishwasher detergent to five gallons of water.
Are the measurements for TSP and/or dishwasher detergent for solid (powder) or liquid? I can not find TSP liquid--everything is called TSP "substitute" now. Are these substitutes OK for cartridges?