Question about slam and morning sun

Jul 20, 2013
299
Northeast
I don't know what time sun comes out, but it's already out a little after 6 am.

I've been slamming for the past few days, testing water after 7 am.

Could this little bit of sun be affecting the results?

My cya is still registering, but according to my math it should be 30, 40 at most.

My overnight FC loss has been somewhat consistent for the last few days, it's 2.5ppm with CC 0-1, but mostly .05

Last night I accidentally overdosed, raised FC to 15 ppm instead of 12. (2 gall instead of 1,5). This morning my FC 11 with CC 0.5.

According to my notes, I had an overnight FC loss of 1 when FC was 10 at night.

Since my CYA is still registering, could the higher dosages of chlorine by used up quicker and overnight loss be greater than 1?

CYA - registering. (Was ~~0 when opened, 30 6 days before opening)
PH 7.5 (was ~7.2 or less when opened. ~7.7 6 days before opening. can't explain the drop)
TA 90 (jumps between 90-130)
CH ~~230 (was 180-200 when opened. can't explain the rise)
FC 11

The only 2 chemicals I've been adding since opening is chlorine and stabilizer.



Below is already posted in another thread. But here's a brief summary:


My CYA was killed within the last 6 days before the pool opening - it was 30 and 6 days later ~~0. I ran the pump with cover on and I suspect maybe something contaminated the water, although the filter cartridges were cleaned last fall (don't know if I need to let them dry before I put the filter cover on, or bring them inside for the winter?)

There was no algae that I could see. What I had was light brownish like mucus on walls and maybe elsewhere. It was easily coming off with piece of cloth and now it's all gone, I think chlorine got rid of all of it. I still need to inspect the pool light, to see if anything is hiding there.


The only issue that I had for the last 3-4 days - the water is still not sparkle clean. I can see the bottom, but not as clearly as I should.

It's been like this for the last 3 or 4 days now and it seems like no improvements at all. I don't know if 10yr old cartridges can contribute to this water cloudiness or not. Can the registering stabilizer be the reason (don't know how old it was. does it have a shelf life?). Can there be something in the heater that's doing it? (heater hasn't been used for the last 5-6 seasons, but the water goes through it and I can't bypass it)

There's no dirt, or almost no dirt on the floor, maybe some dust but less than what I usually have. No dead algae that I can see. I just removed the light cover, nothing there either.

The water is just not sparkle clear as it should be.


Thanks
 
Be sure you scrub any light niches and behind any non-removable ladders. If they can be removed pull them out and clean them. Also be sure you leave the cover off during the slam.
 
Nikon, good you replied with questions. I do have a couple more and perhaps a thought or two you could consider:
1- Above when you speak of CYA, I can't tell if you're referring to CYA levels as good or bad. Remember that your CYA should be between 30-50
2 - I don't understand how CYA could go from 30 to 0 in 5 days? Did you do a major swap to your pool water? That's very odd.

I wonder if perhaps your CYA reading is off causing you to think you should be at a lower FC than you should be for SLAM? For example, "If: you though your CYA was 30, you're SLAMming at 12. But if you CYA is actually 40, then your FC should be at 16.

I have a cartridge filter as well. I change mine every 1-2 years depending on how successful I am at cleaning it. Having one 10 years seems like a really long time, although I'm not sure that would distort your readings.

Just remember CYA is not a bad thing as long as you are between 30-50. Any stabilizer you add will take about a week to register on your TF-100 test kit.

- - - Updated - - -

Regardless, cloudiness means you need to continue to SLAM. We just need to confirm though readings to ensure you're putting in just the right amount of bleach.
 
Nikon, good you replied with questions. I do have a couple more and perhaps a thought or two you could consider:
1- Above when you speak of CYA, I can't tell if you're referring to CYA levels as good or bad. Remember that your CYA should be between 30-50
2 - I don't understand how CYA could go from 30 to 0 in 5 days? Did you do a major swap to your pool water? That's very odd.

I wonder if perhaps your CYA reading is off causing you to think you should be at a lower FC than you should be for SLAM? For example, "If: you though your CYA was 30, you're SLAMming at 12. But if you CYA is actually 40, then your FC should be at 16.

I have a cartridge filter as well. I change mine every 1-2 years depending on how successful I am at cleaning it. Having one 10 years seems like a really long time, although I'm not sure that would distort your readings.

Just remember CYA is not a bad thing as long as you are between 30-50. Any stabilizer you add will take about a week to register on your TF-100 test kit.

- - - Updated - - -

Regardless, cloudiness means you need to continue to SLAM. We just need to confirm though readings to ensure you're putting in just the right amount of bleach.

I've been using TF100 for a few years now. All reagents were refreshed less than a year ago and I had 2 (now 1) R-0013 bottles from last year. I'm pretty sure my CYA reading is accurate, +-10.
From what I was explained - some bacteria converts CYA to ammonia. I had it happened twice in a row now (never before), but I can't explain why it happens and why it happened within 5 days before removing the cover.
Once CYA is fully registered, I'll know the accurate reading, maybe it is 40

As for the cartridge's lifetime - you are in texas, i'm in northeast. My pool is open 4-4.5 months a year, yours is probably much longer. Taking this into account, can I assume my cartridges should last 2-3 times longer than yours (assuming all else being equal)?

I don't know if I could expect more years out of my cartridges considering I get no dirt in my pool, other than dust. There are no trees, no bushes, nothing around my pool.
 
You're right about the conversion to ammonia. It can happen, and when it does, the SLAM may take a little longer due to the stubbornness of the levels. But the bleach will eventually work. I've seen that posted many times. As for the filter, sure.. there may be a workload difference between ours from different regions. I still think 10 years is a long service life for a paper cartridge filter, but only you would know best since you see it first-hand, and know how much it is in operation. So use your best judgment on that. But even if the filer needed replacement, I don't think it would be the cause of your CYA fluctuation issue. I think the best course of action there is to simply ensure your FC is maintained at the optimum level based on accurate CYA to maintain SLAM and overcome the cloudiness in your water. Even just being off by 10ppm on a CYA reading can cause you to miss the mark on FC (chlorine) thereby slowing-down your effectiveness to SLAM.
 
If the CYA loss was caused by ammonia, it has been neutralized by now if you are only losing a couple ppm's of FC overnight. If the ammonia was still present , you would lose virtually all FC within 30 min. Keep up the SLAM until you have met all criteria of Done.
 

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The small overdose to 15 will cause no harm.

Your CYA discussions are a bit confusing.

When did you put in the last dose of CYA? How much did you put in? Was your test result 0 when you put it in?That'll help.

Secondly, CYA has no bearing on your other parameters other than the ability to preserve FC.....don't equate it with TA, pH or anything else.

Most importantly, continue the SLAM. As long as you lose chlorine in excess of 1 ppm, you have not cleared the pool.

Are you testing the FC right up to the endpoint. Remember, you continue to add drops until the last drop results in ABSOLUTELY no further color change. Subtract that last drop and that is your FC.
 
When did you put in the last dose of CYA? How much did you put in? Was your test result 0 when you put it in?That'll help.

I added stabilizer all at once (in 4 socks, 2 in skimmers, 2 in front of the return) on Memorial day, around 7pm. I added 5 lb (96%) which should add a little less than 30 ppm (30 ppm for 20k gallons. My pool is 22-23k gallons)


6 days prior (5/19) I tested cya with cover on, reading was 30.

On memorial day I removed the cover and re-tested CYA. I could see the dot with full tube. So, if I had any CYA at that point, I'd not know how much. I don't think the dot was getting obscured at all

That's when I added 5lb of stabilizer and been shocking since. I think it was a mistake of adding CYA at that time, I should have kept just shocking instead, but what's done is done.
 
I should have kept just shocking instead, but what's done is done.
Not at all. Having CYA in the pool of 30 ppm is just fine for a SLAM. If you look at the FC/CYA chart, you will see that a SLAM value of 30 ppm FC is not that much higher in FC than if you had no CYA.

Now, you get considerable protection from UV and will use less chlorine than if you had 0 CYA.
 
my only point was - since it looks like I had an ammonia and ammonia consumes CYA, having CYA there just giving ammonia food. but since my chlorine is holding now I guess that's not an issue any longer

( or ammonia consumes only registered CYA?? I'd like to know these details because this is the second year in a row I have this issue and I'd like to know what's the best way to deal with it or avoid it altogether if possible )

Thanks
 
It's my understanding that it's believed that a certain bacteria is what converts CYA to ammonia. If you had ammonia it would consume massive amounts of chlorine during a SLAM (not CYA). The ammonia doesn't consume the CYA the cya gets converted to ammonia.
 

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