Robelle 1 Qt. 3-Month Algaecide for Swimming Pools

I've used this algaecide before, I knew how well it works. It did not disappoint. I was ready to drain my pool and start over and remembered this product. It is a 2 pack. So I used one bottle to treat the problem and now have a back up.. Sparkling blue pool. We've just had so much rain and cold weather in the Northeast I think this has been the hardest year I ever had opening the pool.. This stuff is hard to find but worth every cent- it is expensive.