By this I assume you mean that if you were to use Trichlor tabs/pucks then one could raise their FC target as the CYA climbed, but when the FC got high then the pH test would be hard to read. Yes, that is part of the problem but there are other ways to manage the CYA buildup such as doing a partial drain/refill to dilute the water to lower the CYA level (some of this happens from backwashing filters or from summer or winter rain overflow), or use of supplemental products to prevent algae growth if one does not maintain the FC/CYA ratio. There are a lot of pools that use Trichlor and some are lucky enough to have water naturally low in phosphates so don't see algae while others have problems and spend money trying to resolve them. What we propose with a targeted CYA level and using chlorinating liquid or bleach as the primary source of chlorine is the most consistent and stable approach, but it does take a small amount of regular effort to dose the pool regularly.