Best Way to Add CYA

[Watermom]

You can just buy some CYA and add it outright instead of using dichlor if you want. You may have to buy it from a pool store, but just don't buy anything else while you are there. You might find it at Walmart or someplace. It might be called stabilizer or conditioner but if the ingredients say cyanuric or isocyanuric acid, it is the right stuff. Add enough per package directions to get to about 40 or so. Add it slowly to the skimmer while the pump is running and then do not back wash your filter for at least a week and run the pump 24/7 for four or five days while it is dissolving.

Another option is to just use the dichlor that you have on hand to add the CYA as you chlorinate. Though your chlorine level was 10ppm when you tested, it isn't going to stay there if you currently have no CYA in your water. So, as you need to add more chlorine, your dichlor will gradually be adding CYA. Monitor your CYA level every couple of weeks and when you get to 50ppm, switch to either bleach or liquid chlorine.

A third option is to add some CYA now to get to a reading of about 25 or 30 and then to use dichlor for awhile to get the rest of the way up to about 50.

[waterbear]

The dichlor will add 9 ppm CYA for every 10 ppm FC so if you are tryng to clear a green pool dichlor is a good choice since it dissolves (and therefore adds CYA) very quickly! You don't really have to wait for the CYA level to come up. It is there as soon as the dichlor dissolves (which is usually before it can hit the bottom of the pool when broadcast on the surface of the water.) Just shock with the dichlor until the pool is not longer green. If you have no CYA in the water your 10 ppm FC wion't last long and if you are still clearing the pool it won't last long either!

Dichlor is going to get CYA in the water much faster than adding CYA so if you need some in the water fast (and also since you have the dichlor on hand) I would suggest using it.

In a 22000 gal pool each pound of dichlor will raise your FC by 3 ppm so using 10 lbs total over time will get the CYA to just under 30 ppm (27 ppm to be exact). 11 lbs of dichlor will get raise the CYA 30 ppm so by using a total of 11 lbs to chlorinate and shock with instead of any other chlorine sources will get your CYA up pretty quick.