Welcome to TFP! Sounds like you know how your CYA got so high. Now to balance the water properly you'll want to be sure to test your own water with a TF-Series test kit (link in my signature) or Taylor K-2006C. Then you can take proper action to not only lower the CYA, but also to begin the SLAM Process to eliminate algae once & for all.
Welcome to TFP! For a wealth of pool care information please check out our free Pool School. If you are in need of specific help then we encourage you to Register and ask us here in the forum!