Don't worry about the phosphates--that's a new, improved way for the pool store to separate you from your money. Ignore them. The CYA went up like that because of the use of trichlor pucks--they'll raise CYA in a hurry if you don't keep an eye on it, which is why they tend to get people into trouble.

If you have an iron filter before the pool, odds are you're removing most of it before it gets into the pool. However, once it gets into the pool, you can either add metal sequestrant, which keeps it into solution (but does not ever remove it from the pool), or you can run the water past a high chlorine source and intentionally precipitate the iron (copper, manganese, whatever) out onto a filter. Your call--I don't have much experience with metals but there are folks in the metals forum (specifically pooldoc and mbar) that do.

As far as letting the algae break down the CYA--I don't recomend that route, but again, it's your pool. The problem with that method is that the bacteria break the CYA down into ammonia and other byproducts. So when you open the pool, you're going to have to maintain your shock level for a long time to both clear up the algae bloom AND break down all the ammonia, and it can take LOTS and LOTS of chlorine to do so. I think you'd be better off just to chlorinate with bleach throughout the winter and just drain off as much water as you can as it rains or snows in your area, allowing the rain/snow to do your refill for you. The CYA will come down that way, and by the spring should be very manageable. You just may have to consider a different method of chlorination than trichlor for next summer!


Janet