Last night we performed our first OCLT after draining and refilling the pool on Saturday. Yesterday afternoon I checked the FC and it was low at 2.5 ppm. I added Cl and checked again at about 11 PM and it was 5.5 ppm. This morning, we were down to FC 4.0. CC for all the tests since the re-fill has been 0. Other measurements: pH 7.6, TA 110. We changed out about 50% of the water and our CYA reduced from 90 to 34. We also received a lot of rain last Wed/Thurs which may have contributed to the lower CYA. Prior to the water change, we had some small spots of visible algae near corners, stairs, etc but the water was very clear. Water is still very clear and I do not see any visible algae, but clearly something is consuming our chlorine.
I have read the SLAM instructions on SLAM - Shock Level and Maintain - Trouble Free Pool and found that we will need an FC level of around 14 based on our current CYA of 34 at Chlorine / CYA Chart - Trouble Free Pool. Wife and I will stock up on chlorine tonight to prepare to SLAM over the new few days. My plan is to lower the pH when I get home to the recommended 7.2-7.5 with muriatic acid and then do the first dose of Cl / bleach. I hope to get 2-3 doses in tonight before bed and then another in the morning before work. Would it be okay to then check it when I get home at 5 PM or is that too long of a gap? I assume I should take out the pool cleaner unless it is actively in use to get debris off the bottom?
Any other tips that I should be aware of? Thanks!
I have read the SLAM instructions on SLAM - Shock Level and Maintain - Trouble Free Pool and found that we will need an FC level of around 14 based on our current CYA of 34 at Chlorine / CYA Chart - Trouble Free Pool. Wife and I will stock up on chlorine tonight to prepare to SLAM over the new few days. My plan is to lower the pH when I get home to the recommended 7.2-7.5 with muriatic acid and then do the first dose of Cl / bleach. I hope to get 2-3 doses in tonight before bed and then another in the morning before work. Would it be okay to then check it when I get home at 5 PM or is that too long of a gap? I assume I should take out the pool cleaner unless it is actively in use to get debris off the bottom?
Any other tips that I should be aware of? Thanks!