Chlorine Stabilizer (5 lbs) CYA
Stabilizer is used to slow downs the suns ability to turn the chlorine in the pool back to salt. Stabilizer slows this process down so the chlorine stays in your water longer. Chlorine don't just dissappear, it turns back to salt (NaCL).
For all outdoor pools using Chlorine to sanitize
Not needed on indoor pools
Stabilizer levels should be kept between 50 to 80 ppm
Check Stabilizer often and especially if your chlorine is dissappearing
Use 1 lb per 4,000 gallons of water. This will raise your level 30 ppm