Chlorine stabilizer protects chlorine from the degrading effects of sunlight. Reduces chlorine consumption. Essential for swimming pools utilizing gas chlorine, liquid chlorine (bleach), and calcium hypochlorite tablets or granular for chlorination. Cyanuric acid level should be maintained between 30 ppm (parts per million) and 85 ppm. 1-1/2 Lb. of chlorine stabilizer per 10,000 gallons of water will raise cyanuric acid level 10 ppm. No. F081004032PC: Size: 4 Lb., Form: Granule, Pkg Qty: 1, Package Type: Pail No. F081009036PC: Size: 9 Lb., Form: Granule, Pkg Qty: 1, Package Type: Pail No. F081025025PC: Size: 25 Lb., Form: Granule, Pkg Qty: 1, Package Type: Pail Thanks for shopping Hipp Hardware Plus's Online Store for all your DIY and Home Improvement needs. Remember Hipps Help!