I was actually responding to your question of why you should not "shock the heck out of the pool" so next time someone gives you that advice you will have a good reason not to shock without testing and why you should test and have knowledge about your pool. As most people just rely on pool store testing and say "why are you spending all that money on test kit when pool store does it free and is more accurate because it is computerized", which you already were able to see pool store was not very accurate reported your CYA as 10 when it was 30. Yes the CYA/chlorine chart is exactly for that purpose, but most people do not even know the CYA/ chlorine chart exists. As long as you follow guidelines of this forum you are good, but your friends (or at least mine) are going to tell you that you do not have to do that, just do what pool store or pool management company says to do. Now you have one good reason why you do not do that but control and understand and manage your pool better than the pool store.
PS, also next time SWG goes bad, you will be testing occasionally and know it way before the pool goes green and supplement with chlorine til you get it fixed and never miss a day of swimming.
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