thx removed lights from niche & cleaned with brush were dirty with slime, brushed and vacuumed. added chlorine up to 24ppm
UV light rapid free chlorine level dropping
- Thread starter Trader7111
- Start date
12:14 FC:20.5 CC:0 added 5ppm to 25.5ppm of FC still losing 5ppmFC in 1:30 , now holding higher levels & for longer times...
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2:50 FC:19 CC:0 tested for ammonia--0 great Fc loss5ppm over 2:50 improving.. adding 5ppm back up to 24ppm
5:50 FC:17 CC:0 went from 24ppm to 17ppm loss 7ppm in 3 hours, 2.3 per hr adding 7ppm backup to 24ppm should I be holding more FC during 3-6pm & 3 hours of sunlight in northeast? only way to tell is OCLT tonight?
6:15 FC:14 CC:.5 …..from 10:30 to 6:15 21-14 loss 7ppm….so added at 6:30 20ppm chlorine.. 34ppm any thoughts?
after testing 30min after last add of 4 gal 12.5% chlorine (new fresh) FC: only hit 27.5ppm & not 34ppm??? 30min of the 7ppm loss?? so chlorine not 12.5% or what?
what would cause you to lose 7ppm in 30 min? this is almost the same loss over night.
what would cause you to lose 7ppm in 30 min? this is almost the same loss over night.
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Has all this 12.5%? came from the same source, does it have pack date information on the bottles? If not it may be old stock and has lost strength, you probably know this, but liquid chlorine should be stored in a cool place away from bright light, the the stronger it is the shorter its shelf life.
Are you ever checking to make sure you actually hit your target when dosing? Perhaps your pool volume is off or, as mentioned, your bleach strength is off....
yes same store, yes its new stored correctly.
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yes wait 30min for mixing retest
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yes wait 30min for mixing retest
I'd only be guessing, Trader, but fresh to you doesn't mean fresh to the store 
I suppose its also possible that "something" is fighting the chlorine when you add it...and then after 7 ppm gives up...
I'm optimistic, however, with your progress. If you keep at it a bit more I'm hopeful you'll hold better overnight tonight.
I do find it interesting that you overnight loss was identical to your immediate loss...though cant really fathom what this might mean exactly
I suppose its also possible that "something" is fighting the chlorine when you add it...and then after 7 ppm gives up...I'm optimistic, however, with your progress. If you keep at it a bit more I'm hopeful you'll hold better overnight tonight.
I do find it interesting that you overnight loss was identical to your immediate loss...though cant really fathom what this might mean exactly
the only other possible contamination & its VERY possible, is that I have a small water pond upwind but we have not had any wind in last 2-3 days. maybe cross contamination is occurring. weather has been overcast last 2 days also. small pond 10" away. so may need to rip pond out, which would take some doing.. its blue stone masonry with vinyl liner…fish plants…. also have had this pond for the same amount of time as pool.
at some point I may have to accept the fact that FC of 4-5 as maintenance & a CC of .5 is as good as it may get??
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If your cya is 50 ppm then in accordance with our cya:chlorine chart your daily maintenance range should be 6 with a min. Of 4. Having .5 cc is no real biggie since in that range, the chlorine is killing anything that gets into your pool...so no reason to rip out pond....but lots of reasons to never let your FC get below 4 at a cya of 50
Not sure why this would be tantamount to "accepting the fact" in your post...it's a normal TFP parameter and while its wonderful to have zero cc it only becomes problematic if your ccs are higher than 1.
So, in the past when you were struggling with high ccs, were you maintaining your chlorine daily in accordance with cya chart, or were you using a different method to maintain your pool? If going forward once your slam is complete, you have 50 ppm cya, add chlorine daily to maintain above 4 ppm (eg I add in the morning to bring my own up to 7 and generally might lose about 2-3 depending n weather and bather load) I suspect over time you would find things stablized.
Not sure why this would be tantamount to "accepting the fact" in your post...it's a normal TFP parameter and while its wonderful to have zero cc it only becomes problematic if your ccs are higher than 1.
So, in the past when you were struggling with high ccs, were you maintaining your chlorine daily in accordance with cya chart, or were you using a different method to maintain your pool? If going forward once your slam is complete, you have 50 ppm cya, add chlorine daily to maintain above 4 ppm (eg I add in the morning to bring my own up to 7 and generally might lose about 2-3 depending n weather and bather load) I suspect over time you would find things stablized.
Thx swamp woman I agree. I was meaning with accepting the fact that I may not get <1ppm overnight & I may need to accept a maintenance of FC:4-7ppm with CC: .5 and a greater than > 1ppm loss overnight.
Oh, gotca, misunderstood
Ps, re my maintenance note - my pool is shaded in part by a landscaped terrace...if your full is in full sun all day, you could eaily use up more chlorine than I do I was just trying to illustrate using example...too any variable o predict what is "normal" for YOUR pool.
With the proximity of pond and in full sun plus your UV, it may wll be that what's "normal" for your pool would be to require a higher daily dose of chlorine and to expect to lose more than half of it daily.
What's not normal was that you were not holding chlorine previously, and smelled ammonia, and had very high ccs Unless you were only dosing to 1 pm for example, or under-dosing to the point you were constantly battling nascent algae and didnt know it.
Ps, re my maintenance note - my pool is shaded in part by a landscaped terrace...if your full is in full sun all day, you could eaily use up more chlorine than I do
I was just trying to illustrate using example...too any variable o predict what is "normal" for YOUR pool.With the proximity of pond and in full sun plus your UV, it may wll be that what's "normal" for your pool would be to require a higher daily dose of chlorine and to expect to lose more than half of it daily.
What's not normal was that you were not holding chlorine previously, and smelled ammonia, and had very high ccs
Unless you were only dosing to 1 pm for example, or under-dosing to the point you were constantly battling nascent algae and didnt know it.not going to test all day just going to add 1gal of chlorine every 3 hours (12:30 start) test at 9:30 adjust & see what happened Monday
There is not a direct relation between CC and the amount of FC that gets used up. Chlorine can oxidize a chemical quickly enough to not have a lot of intermediate chemicals that register as CC. Combined Chlorine (CC) is when chlorine attaches to a chemical to become part of it, but if additional chlorine more fully oxidizes the chemical to release that bound chlorine, then you won't see any CC. As shown in this post, even when I had a bacterial conversion of CYA to ammonia, when I added chlorine it did not just produce CC even though normally adding chlorine to ammonia should produce monochloramine which shows up as CC. I did show up some CC, but most of the CYA had apparently been only partially degraded so chlorine that I added would oxidize it without sticking around very long (if at all) as CC. I ended up using cumulatively 56 ppm FC even though the peak CC was only 1.6 ppm.
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No it would not be normal to have > 1 ppm FC loss overnight, especially when not at SLAM levels of chlorine. Also, if you have 4 ppm FC daily loss of chlorine, that is also too high.
Did you ever determine both the daytime and the overnight losses with the pump/circulation turned off so that you could eliminate the UV system from affecting the results? If you have normal losses without circulation, then you should seriously consider unplugging/disabling the UV system and see what happens then.