Hi, i have a 40,000 gallon pool. We just opened it about a month ago and it's been a struggle to get chlorine to even slightly show up. We tried putting a very high concentrated shock bags into the pool a week ago and no chlorine. And yesterday we bought even more. Still not a trace of chlorine. The water is very cloudy and we are planning a pool party this thursday. I hope you guys may be of assistance to us.