Rx Clear C3 3" Stabilized Chlorinating Tablets for Swimming Pool and Hot Tubs, 25 lbs Made of 99% Trichloro-S-Triazinetrione and 90% Chlorine. Contains cyanuric acid (CYA), a stabilizer that prevents UV light from removing existing chlorine Safe to use on swimming pools, spa, and hot tubs Eliminates contaminants keeping the water clean and crystal clear 1 tablet treats 10,000 gallons of water for up to a week
