Until yesterday I had a brown-black swampy pool due to algae and pool cover failure. I went to the local pool store and was encouraged to purchase green-to-clean for the algae because my pH was 8 (FC 0, CC 0, TA 120, CYA 0). I was instructed to add it, followed by 2 bags of calcium hypochlorite, wait 12 hrs and add another bag, and repeat in another 12. The pool water didn't do anything with the chlorine application; no FC and continued to smell like sewage. My thought was with no FC either the algae is really feasting or it's so contaminated it can't hold a level with such minimal chlorine added (logical to me). I called the pool store and got an unsure answer so I preceeded to add an additional 7 bags of shock. Pool water is now a different shade of milky green but continues to smell bad and shows no FC (pH is still 8+). Unfortunately, I will have to wait until tomorrow to check CC. So what's the deal with the minimal amount of shock that is supposed to be added over 24 hours? My swamp and that amount didn't compute.
Green-To-Clean Help
- Thread starter becky
- Start date
Hi Becky, welcome. 
Please start with this article on Defeating Algae. Then read the other articles in Pool School, like How To Shock your Pool, and you'll have your answer. If you still are uncertain, post back here and we'll assist you.
Please start with this article on Defeating Algae. Then read the other articles in Pool School, like How To Shock your Pool, and you'll have your answer. If you still are uncertain, post back here and we'll assist you.
Rubygrrl
0
I'm new--but it seems you need to get your CYA up--otherwise all of your chlorine is going to be lost to the sun. 
I agree. Maybe get your CYA up to 20 or so (i.e. add about 2lb) while you're whacking the algae, then get it up to 30-50 afterward. (another 2lb).Rubygrrl said:I'm new--but it seems you need to get your CYA up--otherwise all of your chlorine is going to be lost to the sun.
--paulr
green to clean creates monocloramine when chlorine is added. Monochloramine is one of the more common forms of CC. Since it is a nitrogen containing compound the algae consume it and die. It does work but not in cases where you have a stinky green swamp. It works in cases where the algae is from too high a CYA by temporarily taking the CYA out of the loop. However, it's a bandaid and not a fix. In your case you just need a LOT of chlorine until the pool clears. You will actually need more now since you used the green to clean and have to kill the monochloramine you formed than if you had not put it in.
I would bring the CYA up to 30 ppm and shock to 15-20 ppm and keep it there until the algae is dead. Once the pool is clear and there is no CC you can bring the CYA up a bit higher to 40-50 ppm. With a sand filter I would go for 50 ppm because you will lose CYA with each backwash.
I would bring the CYA up to 30 ppm and shock to 15-20 ppm and keep it there until the algae is dead. Once the pool is clear and there is no CC you can bring the CYA up a bit higher to 40-50 ppm. With a sand filter I would go for 50 ppm because you will lose CYA with each backwash.