A stupid "old bee" question

I have been reading posts that the chlorine level needs to be higher than "normal" based on your CYA level. I was hoping someone might be able to explain this to me.

My CYA is somewhere around 30-40 and I have always kept my chlorine level between 1-2ppm. If I read correctly I should be having some serious problems in my pool at these levels. I am in year 9, and knock on wood, I have never had any algea, slime, or any other problems. So, why should I keep my chlorine levels higher?

I use a 50/50 mix of trichlor tablets and bleach (not mixing them of course, talking about the % of chlorine added). I do this to allow me to not have to deal with pH issues. Bleach tends to raise my pH while trichlor tends to drop it, so by providing roughly half the chlorine from each source my pH stays stable. I just periodically add 20 mule team when we have heavy rains which tend to drop pH.

The levels are in what is called a "Best Guess" table. If you haven't had problems, then you don't have a problem.

These are empirically determined values that seem to be most effective. It's not guaranteed that you will get algae with FC=2 at CYA=35. If you don't see CC turning up, and you don't get algae then you are probably fine.

People, however, frequently come to our guidelines because they DO have a problem and their old methods or pool store or pool service advice just doesn't work.

Again, it's a "Best Guess".

You probably also stay ahead of your pool.

Miss a day or two and see what happens.

Also realize that most state Health Departments now require a minimun of 2 ppm FC in a pool with no stabilizer because of recent research on kill times of some water borne pathogens. It's not just algae that you want to keep out of your pool.