No chlorine loss overnight but big loss during the day ?

#1
Guys, I have a CYA of 60 so my shock level is 18. I'm trying to keep the pool above that level so I added chlorine last night. The test showed FC of 23. This morning I tested and got a reading of 23 again. My first time of having no loss overnight so I was certainly encouraged.

I added no chlorine this morning since it was at 23. I tested just now and got a FC number of 12.5. It was sunny and 90 today but geez. Basically a loss of 10 during the day ? Now I'm concerned all over again.

I'll test again tonight and tomorrow morning to see where I am. Should I lose this much chlorine during the day ? I thought maybe I was done fighting this.

The pool is slowly getting more clear it seems. I've been brushing it and vacuuming every day. Right now I can see the 3rd step down on my wedding cake steps more clearly and I can see the outline of the 4th step. An improvement over yesterday.

Thanks for the continued feedback. Hopefully I'm not wearing out my welcome.

24' Round A/G Pool with Sand Filter

Steve
 

mas985

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#2
I know that I get about 50% extinction with a CYA of 45 so 40% extinction with a CYA of 60 might be reasonable. Also, the CYA measurement is somewhat subjective so you may not have exactly 60. I think all are probably within the accuracy of the measurement.
 

frustratedpoolmom

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#3
Steve, you still can't see the bottom? Anyway you can post pics? Is it cloudy? Clear and cloudy? Blue and cloudy? Green at all?

I'm inclined to agree with you, that seems like a really high loss, even during the day. Was anyone swimming?

I'm glad it held last night, that's a good sign....
 
#4
I'll take a pic and post it in a few minutes here. It's very blue, no green at all. Just cloudy enough that I can't see the bottom.

No, no swimming. We haven't started that at all yet. The only person in the pool at all is me to do the brushing once a day.

Can't see the bottom at all yet. Can see further down into the pool than before but not the bottom. Will be interesting to see if I get a drop overnight tonight. I want to bring the FC back up this evening though. Afraid to let it come down to normal levels before I know all the work is done.

Steve

Batteries in my dig. camera are dead. So I'll take a couple pictures tomorrow and post. Thanks.
 

frustratedpoolmom

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#5
Any chance at all either number were testing errors?

I guess another night if it holds, you'll know if your in the home stretch.... and it just has to filter out....

hmmmm....frustrating isn't it? It'll be worth it when it's sparkly. :wink:
 

JasonLion

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#6
If you got a good bit of direct sunlight on the pool and the water temperature is high then that chlorine loss, about 45% of your chlorine in a day, is reasonable.
 
#7
Yeah, I have no trees near the pool so by about 10am the sun is on the pool and stays on it until 5pm at night when the house starts to block it.

Thanks for the feedback guys. I went ahead and got it up to shock level again tonight. I'll test again before I go to bed and again in the morning for another comparison.

I'm also not backwashing. The pressure reads 16 and has stayed that way for a couple of days. I don't want to backwash too often so I'm just leaving it.

A drop of 45% chlorine from 5 to 3 or something would be fine -- when I'm not shocking. Add a little bleach and I'm back to where I want to be. It's only painful to see that kind of drop when you're shocking and so much is needed to boost it back up.

Steve
 
#8
Very disappointing. When I got home yesterday my FC read 12.5 so I'd lost half of it from the morning reading. I added 2 of the large jugs of bleach and gave it about 90 minutes to circulate before testing. I tested twice last night with two different water samples and showed my FC as 24.0 in one test and 24.5 in the other. This morning it read 19. My CC had been reading 0.5 every time -- it was never clear but it never took more than one drop to get it clear. This morning it took two drops so somewhere closer to 1.0.

I guess I'll buy a lot more bleach and try to get it up above shock level again and hold it there. I didn't have any to add this morning so it's going to drop a lot during the day. Held it between 18 and 24 for almost 3 days and it's still consuming chlorine overnight ? This is frustrating.

Steve
 

DLO

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May 28, 2008
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Sioux City, IA
#11
Hey Steve.....are you shocking with bleach only? The reason I ask is that before i converted to BBB exclusively, I used Cal Hypo to shock with. The last time I used it, I had blue, cloudy water for a week at least. I maintained my shock level by adding bleach as I lost FC during the day, but the initial rise to the break point was with Cal Hypo. I've had clear water even during shocks, after I started using bleach exclusively.

As far as my experience with FC loss....my pool is like yours, exposed to sun all day. My CYA is a bit lower than yours (48) and I lose close to 50% FC during the day. I add enough bleach to bring FC to around 10ppm in the morning and have an FC of 5 or so in the evening with no loss overnight. We are getting a Cover Pools auto cover installed next week so I expect my FC consumption to drop soon after that.
 
#12
About two weeks ago I used shock from the pool place here locally -- granular. That did turn the pool from green to blue in about 24 hours. I've used bleach exclusively since then.

I got my water tested today just to compare my results with something:

Ph 7.6
TA 140 -- High enough to cause cloudy water ?
CYA 70 -- Also higher than what I want, especially in trying to shock the pool
Copper 0 -- Was happy to see that, hadn't had it tested before

I vacuumed to waste tonight -- I want to add some new water to hopefully dilute things a little and get the CYA and TA numbers down. Hopefully a few days of doing this will help. I'm sure the high CYA number is part of my issue. I need a lot more chlorine to win the fight so it just makes things that much harder.

I forgot to get batteries tonight when I got my bleach so I'll post a couple of pictures tomorrow.

Thanks for helping an impatient newbie keep his spirits up ! That's half the battle.

Steve
 

frustratedpoolmom

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#13
Steve, my TA is 120, I don't think that is causing a problem for you.

I'd be curious to see what your CYA result on your own test is after you backwash. Have you seen the thread that Joyce posted showing the picture of the CYA test "finished"? It was quite helpful to see, since for so many it seems to be "up to interpretation".

I'm going to retest mine tomorrow, I've been so busy. I don't think my dot ever "completely" appeared and I'm betting my CYA is closer to 60.

POP! Please pass the POP to Steve.... :mrgreen:
 
G
#16
ssmith1627 said:
Ph 7.6
TA 140 -- High enough to cause cloudy water ?

Steve
To know if a TA of 140 is high enough to cause cloudy water we also need to know your calcium hardness. It might be if the calcium levels are high enough even with a pH of 7.6.
 
#18
No, I probably never did post that simply because I have an above ground pool and think of that reading as secondary.

The CH reading from the pool place today was 175. (on a side note, I think I found a decent pool place -- they tested the water without trying to herd me into clarifiers or who knows what else)

I'll do another CYA test tomorrow evening to see how close I come to what the pool place gave me. They're probably testing the same way as I would at home, right ? Makes sense that it could be a false high reading with already-cloudy water.

One other thing -- just to try to put these pieces together in my own mind -- with the chlorine, we're trying to oxidize anything that's in the pool. Basically burn it off. As opposed to a flocculant where we'd hope to get it to drop to the bottom and then vacuum it out. Do we ever get to a point that the CC reading is clear after the 5 drops ? I see so many people posting zero there but mine is never that. A couple times it has been 1 but every other time is takes 1 drop to get to clear so it's something less than 0.5.

Thanks again guys. The continued conversation is a great help in trying to get my mind around all the different concepts.

Steve
 

JasonLion

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#19
Yes, CC really does go to zero. There are a couple of possibilities as to why why yours is never zero. You might not be doing the test quite right, the final drop to clear the pink should bring the sample to completely clear. Sometimes the sample goes to a very light pink that is almost clear and if you miss that drop CC will test as 0.5. Your FC level might be too low. You might be adding something to the water that forms CC, as some sequestrants do. You might have unusually high levels of pollen forming CC. You might have a low level of extremely persistent CC that will only be cleared out by shocking.
 
G
#20
The CH reading is NOT secondary. While it is true that you do not need the same levels of calcium in a vinyl pool you still need to know your calcium hardness. If it is high you can stil get scaling or cloudy water. If it is very low your water might have a tendency to foam. I think there is a misconception that because you do not need 200-400 ppm calcium for a vinyl pool it means you do not have to test your calcium levels. This is just not true!