Help w/ Chlorine loss

Chlorinating, maintaining the right chlorine levels,
chlorine problems. Dichlor, trichlor, cal hypo, bleach,
granules, chlorine pucks and chlorine sticks.
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gto
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Help w/ Chlorine loss

Postby gto » Mon 26 Jul, 2010 01:34

So many threads on this here, but mine seems odd. Chem Geek, please help
Levels for the most part seem good, but I cant seem to hold any chlorine an hour after I dose, & this is at night! I used 3/4 gln of 12.5 liquid. & I read TC of 5.0 10 min after the dosage. An hour later, my TC read 0.5.
I added 23 lbs of CC today, rather rapidly. 15lbs, & then another 8lbs an hour later after I confirmed rise of CH (hope that wasnt a mistake. I didnt see anything online that said it couldnt be added all at once)
My CH level before the rise was 130ppm, & I had to bring that up. I was holding Chlorine levels fine prior to the add of the CC (about 1ppm loss from night read until morning read)

My readings are as follows.

18000 gln non-SWG / Plaster ovr Gunite
Water Temp: 84
Outside Temp: 65
PH: 7.6
TA: 100
CH: 250
CYA: 28 (I know it's low, but it's nighttime that I added chlorine & tested an hour later)
TDS: 300
Phosphates: 0 :thumbup:


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Help w/ Chlorine loss

Postby chem geek » Mon 26 Jul, 2010 01:54

I don't think the addition of calcium chloride had anything to do with your loss of chlorine. Did your Free Chlorine (FC) get to zero at any point in time? Did you notice a drop in Cyanuric Acid (CYA) level? If so, then bacteria could have converted your CYA into ammonia which creates a huge chlorine demand. However, if you really had zero phosphates, then that wouldn't normally happen so quickly, but I doubt your phosphates are really zero. If these are all readings from a pool store or from test strips, I wouldn't trust them.

You can do a bucket test to see how much chlorine it will take before the chlorine will start to hold. 1/4 teaspoon of 6% bleach in a 2 gallon bucket of pool water is 10 ppm FC. Or you can just keep adding chlorine until it starts to hold. I write about my own experience with this effect in this thread .
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Help w/ Chlorine loss

Postby gto » Mon 26 Jul, 2010 02:10

Awesome that you got back so quickly, & yes, I think my FC dropped to Zero today for a few hours during daylight. The Phosphate (which may or may not have been tested, there was just a zero on the checklist, so I included it here, & TDS numbers were given by the pool store this morning when I went in to buy the CH up, so I cannot stand behind those readings. As far as the other numbers, I tested using my TF test kit.
CYA into Ammonia?!? ouch! Does that mean I may have no CYA left in the water. I could go test that now, but I tested it Friday, & didnt think it would change from then till now.
How much chlorine do you think I might need, as a guess, & did I create a new water problem w/ the ammonia? I havnt read up on ammonia yet. I will also check your link in a moment.
All this is making me crazy, & I'm frustrated. I dumped half my water cuz I seemed to get a reading of CYA 125 & now I have nothing?
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gto
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Location: SoCal

Help w/ Chlorine loss

Postby gto » Mon 26 Jul, 2010 02:19

I'm reading your thread now. Just want to add, that I dont have a test for ammonia levels. I have the TFtest-100.
Also, the water looks clear & not cloudy. It does smell though more than usual.
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gto
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Help w/ Chlorine loss

Postby gto » Mon 26 Jul, 2010 02:40

OMG!
I just read through that. I cant believe I may have created such a huge problem. I'm such a novice & learning too little too quick. As soon as I feel like some sort of pro, a new issue arrises. This seems worse then where I started when my CYA was too high, & I couldnt hold my FC.
I'm gonna go & test my CYA right now. I do not have ammonia test, so I'm thinking that would at least let me know if it's gone to zero & converted over.
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gto
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Location: SoCal

Help w/ Chlorine loss

Postby gto » Mon 26 Jul, 2010 03:13

I just did a CYA test. Still getting the hang of it really. The indicator starts to get pretty faint at the 30 marker, & then goes barely visible at 20, & I mean barely . . . depending on the angle you're looking at it. probably disappears all-together halfway btween 20 marker & the top of vial. I hope I'm reading this correctly. Does the test have to be opaque to the point where the indicator is impossible to read, & Do you think CYA has converted over to ammonia? It's probably close to the same read I was getting on Friday, at which time I could hold my FC to normal losses.
It's late, & I cant do the bucket test right now. I have 1/2 a gln of 12.5 here at the pad. thinking I might just throw that in the water, run over to the market & buy several jugs of clorox to dump in to try & keep any bacteria outbreak controlled until I can deal with this tomorrow.
Also, at what point do I start to introduce more CYA, & to what amount?
Thoughts?
thx Richard
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gto
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Location: SoCal

Help w/ Chlorine loss

Postby gto » Mon 26 Jul, 2010 06:16

UPDATE

I didnt end up going get the Clorox tonite. Stores are closed.
So i threw in the 1/2 gln of 12.5% in at 1:30
I got a reading of 3.0 TC
2.5 hours later it reads the same with no loss.
I also have an auto chlorinator loaded w/ 7 trichlor tabs running in that period, valve fully open, so with the trickle of chlorine, I'll get a tiny bit of CYA.
I'm thinking that the fact that I have no loss in that time, albeit no sun, is a good thing, & maybe there's still some hope.
Tomorrow morning I will shoot off to get the conditioner, some more chlorine and the ammonia test strips.
More testing tomorrow. I wanna save this half fill that I just did last week, & the $60- worth of CH added just today. My fill water here is 90ppm.
Any suggestions on the conditioner I should get? Which Brand, granular, liquid, etc. I shop at a wholesaler that all the local pool pros go to, & the counter doesnt appreciate much questioning nor claim to know all that much on chemistry. It's an all sales type place & not consumer friendly. While they carry tons of brands, I want to be ready to shop when I arrive.



UPDATE:

11am - FC 2.0
CC .5
TC 2.5
(Chlorinator on since 1:30am) Second guessing my 3.0 read from earlier as my lighting wasnt great, but still happy to see some type of number. Wondering if the ammonia, if present, is eating as fast as I'm feeding it.

UPDATE:

stopped at petco for the ammonia kit. Got this drop one(probably better than strips)
http://www.petco.com/product/8234/Aquar ... SiteSearch

10:30am test: Nh3/Nh+4: 0ppm
Woohoo! Looks like I may be in good shape. No idea why the TC levels were going away yesterday evening.

3:20pm, Chlorine levels are holding at 2.5 with feeder valve all open . . in direct sunlight. I look all good . . . I think. Did another test of CYA, & I'm getting a read of 28ppm. I did it correct this time in the right lighting. Marker deff disapears at high 20's level.
Just shut off the Trichlor feeder, & raised the TC to 4.0 with some LC. I'm gonna get a little stabilizer at the store, & bring her up just a bit. All that's left to do is a FC test, & then a CYA test after a few days. Hopefully everything will hold.
Still scratching my head on the low levels yesterday. Makes no sense.
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Help w/ Chlorine loss

Postby chem geek » Tue 27 Jul, 2010 00:03

From everything you've found, it sounds like the chlorine demand was something temporary and not bacterial conversion of CYA to ammonia or if it was, it wasn't very much. It could have just been the beginnings of nascent algae growth -- in the first day, such growth is often not visible, but it does consume chlorine though it would take more than just a couple of hours to get that far. No matter what happened, you seem to be back on track now so don't worry about it -- just make sure you don't let the chlorine get to zero in the future.
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gto
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Location: SoCal

Help w/ Chlorine loss

Postby gto » Tue 27 Jul, 2010 01:05

Yeah, Zero is a sad number. It wont happen again if I can help it. Doing test this evening to see where it goes. Current read is 4.5.
Got the HASA conditioner box of powder today. will sock it & build some CYA up starting tomorrow. Your reason for loss seems entirely logical, & I'm pretty stoked about the negative NH3 test.
Thanks a whole lot for the scare, lol.
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Help w/ Chlorine loss

Postby chem geek » Tue 27 Jul, 2010 01:42

As for the CYA test and what it should look like, take a look at this link for some photos that show the black dot disappearing. The best lighting is to stand with your back to the sun outdoors and hold the tube in front of you with your body shading it and you looking down into the tube. That is strong indirect lighting which gives the most accurate reading.

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