REBARBEE said:
hi, have had a 18500 gal in ground with haywood sand filter for twenty five years new liner 2 years ago. would lose the pool a couple of times every season, I thought this was the year to try the BBB. I have a ph 7.2 ta 100 ch280 and a cya of 50 (me testing and the pool supply store checking also) I can not get the chlorine readings up. 3 gals last night , a test result of 1-2 this morn and now down to almost 0. any advise i dont want to go back to the tablets. thanks
Welcome to TFP
You are right, you do not want to go back to the tabs because you are at the top recommended CYA level now. Besides, tabs will not allow you to take control of your pool, you need a good test kit.
Read about the recommended test kits in Pool School. The best bang for the buck and the fav around here is the TF100. Link in my sig. You need to be able to test FC/CC (using the FAS/DPD test) on a regular basis and often while you are shocking and 'taking control of your pool'.
If you follow our method, we will teach you how NOT to "lose" your pool at all during any season.
When other pools go green, you just smile and go help them out because, after you learn the ropes, you can help others.
Okay, something is eating your chlorine and no matter what it is, the answer is more chlorine. Go get a lot of plain 6% bleach from wallyworld or liquid chlorine. These are unstabilized forms of chlorine and will not add unwanted side effects. All they will do is clear and sanitize your pool.
With a CYA of 50, your shock level is about 20. So you need to add enough bleach/liquid chlorine to
reach and maintain shock level of 20FC. Use the PoolCalculator.com to figure the doses.
See How To Shock Your Pool in Pool School.
It will be helpful if you add your pool and equipment specs in your sig. Go to User Control Panel (top left under TFP logo), select Profile, then Edit Sig.
Post back in this thread with any questions.
Welcome to the forum