I forgot to put chlorine into the hot tube for a couple of nights and when I next checked, of course the CCs were high. So I started shocking the pool. Right in the middle of the shock I had a death in the family and needed to travel to the funeral. My wife trying to help in my absence, over chlorinated the water. My target shock level is 10ppm. My wife had it up to 20ppm. Today is the first day where it dropped to < 10ppm since I returned home 6 nights ago. I still have CCs of greater than .5ppm. It has been 6 straight days of > shock levels of chlorine and the bacteria is still not gone.
I have to tell you that this hot tub was a "tester" for a real pool and it has been anything but trouble free. I have frequently dumped the spa water and started again. Each time I waste 300 gallons of water, but shocking the water and fixing this bacteria problem has been a constant challenge that I have faced over and over again. In the last year, I have spent more time fixing the bacteria problem than I have enjoying the water. I am sick of it.
I would switch to bromine in a heart beat if I had a clue how to do it. I invested so much time reading and researching how to take care of the water - I understand the testing and treatment procedures recommended on this site, but frequently forget to put in chlorine. The water is so sensitive that if I forget one night there is a good chance that my water has bacteria - if I forget two nights in a row - then my water definitely has bacteria. In a 7 day period I probably forget at least once if not twice and so rarely have water that can be used for more than a week or two at the most.
I am dumping the water again tomorrow - another 300 gallons going to waste and I haven't used the tub in over two weeks waiting for the bacteria to die. I was so excited to get the hot tub - but now after a year of fighting to keep the water usable, I am so frustrated that I hate even talking about it.
I will never get a real pool.