Chlorine test starts clear, then turns bright yellow

[werd98]

Hi everyone! I've never owned a pool before, but have really enjoyed reading this site!!

My pool became slightly cloudy a few days ago, so I've been adding chlorine. This has worked great, and I'm about 95% clear. However, when I test using the "add 5 drops and see how yellow" method (got the TF100, so much better!), the water stays completely clear for a few seconds, and then starts to get more and more yellow. ISTR the instantaneous is FC(?), and then a while later you're actually looking at something else (CC?), is that right? Before the cloudiness, each drop would be a bit yellow right away.

Anyways, here are my readings:
FC 0?
CC ?
pH 7.5
TA 200
CH ?
CYA 0

Here's the "add" portion of my log:
6/13/2013 19:30:00 add Added about 100 oz of 10% bleach
6/14/2013 10:00:00 add Added ~300oz of 6%
6/14/2013 21:00:00 add Added 128 oz of 8.25% bleach

Am I adding bleach too quickly?

Also, since the pool cover is open less than an hour or two a day, I wonder how long I can stay at a really low CYA? I've gone through a 7 lb tub of 3" Trichloro chlorine tablets already last month (which add CYA, right?), so I don't really think I'm at 0 CYA. Is there a benefit to staying super low?

 

[jblizzle]

No real benefit to staying super low on the CYA, lots of benefit to getting up to 30ppm.

So you have the TF100 or not? Post up the FAS-DPD test results.

And yes the pucks add CYA, use poolcalculator.com to see how much they added.

 

[werd98]

Should I keep the cya low until my water is back to clear, or should I add the cya right away?

 

[jblizzle]

Usually good to get to 20-30ppm for the shock process so there is some protection from the sun. You may benefit from having the cover off some during the day to help any CC burn off. Actually you gain more heat with it off as well if it is sunny and calm.

 

[Isaac-1]

For shocking it is best to have a CYA of around 30 ppm, this gives you some sun protection, but also keeps your shock level target FC down, so best of both worlds. Once you get your pool all cleared up, and you are done shocking you can raise your CYA up to the 40-50 ppm range for manually chlorinated pools exact amount depends on the amount of sunlight your pool gets, if mostly shaded, or if you keep it covered most of the time when your not swimming you might want just keep CYA at 30 ppm.

Ike

 

[werd98]

Sounds good - I've just poured about 32 oz of CYA into the skimmer, and will pour 32 oz more in tomorrow. Two pool stores said to use 128 oz, and the PoolCalculator said 96-100 oz (to go from 0 to 20).

I know it won't fully dissolve for up to a week, but I'm curious to see how much is already in the water tomorrow.

Any thoughts on the chlorine test color progression?

 

[Charlie_R]

If you have the TF100 or K-2006, both use FAS-DPD. You aren't looking for a color, be it yellow, orange or whatever. 10mL or 25mL sample. With the DPD powder, sample turns pink to red, depending on your chlorine level. Add FAS drops to color CHANGE to totally clear.

Are you SURE you are doing the proper test, with the proper reagents?

 

[Isaac-1]

It is not so much that it takes up to a week to dissolve (although it does dissolve slowly), as it takes up to a week after dissolving to register. Chem Geek has posted the scientific reasoning at some place around here, but the simple version is something like once dissolved it still has to convert from A to B in the water before it shows up on the test.

 

[Patrick_B]

You need to stop adding CYA until you are sure what you have. It isn't and wasn't 0.0 after 7 lbs of tabs were put in. Maybe not much, but not 0.0. I'm wondering too if you are adding the correct reagents and or testing correctly on all parameters.

The "see how yellow" test is the OTO method that shows only Total Chlorine and does not differentiate between FC and CC. Why it would get cloudy is beyond me, but someone else may know. I honestly don't use that test kit much, so I have not encountered that. Please run your FC and CC with the TF 100 method for FAS/DPD method. Pink to clear, then add R-0003 for possible pink again, and back to clear. Let us know what you find then.

We can't answer too many questions on Chlorine without solid results from that test.

 

[JasonLion]

If the OTO chlorine test starts clear and slowly turns yellow it means you don't have any FC, and do have some CC. You need to shock the pool, as others have suggested.

 

[werd98]

You need to stop adding CYA until you are sure what you have. It isn't and wasn't 0.0 after 7 lbs of tabs were put in. Maybe not much, but not 0.0. I'm wondering too if you are adding the correct reagents and or testing correctly on all parameters.

PoolCalculator.com says it should be at 13, but after filling the tube up all the way to the top with the TF100 CYA test, I could still completely see the black dot at the bottom - that's why I thought it was 0

Please run your FC and CC with the TF 100 method for FAS/DPD method. Pink to clear, then add R-0003 for possible pink again, and back to clear.

For some reason I can't find any of the regents needed for the FAS/DPD? Here's what they sent me (the stuff on the left came with the pool):

 

[Richard320]

You need to stop adding CYA until you are sure what you have. It isn't and wasn't 0.0 after 7 lbs of tabs were put in. Maybe not much, but not 0.0. I'm wondering too if you are adding the correct reagents and or testing correctly on all parameters.

PoolCalculator.com says it should be at 13, but after filling the tube up all the way to the top with the TF100 CYA test, I could still completely see the black dot at the bottom - that's why I thought it was 0

Please run your FC and CC with the TF 100 method for FAS/DPD method. Pink to clear, then add R-0003 for possible pink again, and back to clear.

For some reason I can't find any of the regents needed for the FAS/DPD? Here's what they sent me (the stuff on the left came with the pool):

That big bottle, lower right... does it say R-0871? There should also be a small jar with some chunky powder in it marked R-0870. It appears to be in the middle compartment, left side. The scoop is there, that blue thing by the handle. I don't see the test vial marked "Chlorine Only" but you can use any vial as long as it has marks for 10 ml and/or 25 ml. There should be a small bottle marked R-003. If you have the powder, the vial, the scoop, and the two liquids, you're ready to test.

[center:1d1hmn3k][youtube:1d1hmn3k]PHQG4tgQsFE[/youtube:1d1hmn3k][/center:1d1hmn3k]

 

[Charlie_R]

What are those items with the yellow caps in the kit on the right? The little container standing upright just behind the big bottle looks like it might be DPD powder. Is that container marked R-0870? If it is, there will be another bottle of liquid marked R-0871, and a third small bottle marked R-0003. These would be your FAS-DPD test reagents. See Pool School for how to use these items.

How long has it been since you added the CYA? It usually takes a week for it to show up when testing.

Dang nab it Richard320! beat me to it!

 

[werd98]

That video was perfect! I added 256 oz of 10% bleach at 10 AM this morning (the water still had a very slight haze in the deep end), and now at 12 PM here's what I found:
FC - 7.5
CC - 0
... although the water was still ever so slightly pink after the 15th drop, whoops!
I then added the next round, and the drops didn't change the color at all - it stayed clear (with a tiny pink tint).

Two questions:
1) If my CYA is incredibly low (10 or under), how fast will the sun cause the chlorine to drop?
2) What's the highest FC that's still "safe to swim"?

Thanks for everyone's help - I really appreciate this place!!

 

[jblizzle]

At very low CYA, you can lose 50% of the FC every hour to the sun.

Safe when FC less than shock level and greater than the minimum for your CYA.

 

[UnderWaterVanya]

Keep going until even the slight pink is gone.

Sent via Tapatalk...

 

[werd98]

6/15 5pm
FC: 4
CC: .5

Still trying to get the hang of swirling and adding drops at the same time! Would it be ok to swirl for 10-15sec between drops?

I'm thinking of trying for a target of 20 for my CYA, since we use the automatic cover so much?

Should I be worried about a TA of 200?

 

[Richard320]

6/15 5pm
FC: 4
CC: .5

Still trying to get the hang of swirling and adding drops at the same time! Would it be ok to swirl for 10-15sec between drops?

I'm thinking of trying for a target of 20 for my CYA, since we use the automatic cover so much?

Should I be worried about a TA of 200?

That's too long between drops. You can swirl as long as you want to dissolve the powder, but I'd say about 7 or 8 swirls between drops is plenty. Watch the video.

[center:2159aehq][youtube:2159aehq]PHQG4tgQsFE[/youtube:2159aehq][/center:2159aehq]

 

[werd98]

6/15 5 pm:
FC 4
CC 0.5

6/16 11 am
FC 2
CC 0

Did the test three times this morning first time, I put in r-0003 instead of 871; second time, I knocked the vial over after getting the FC reading of 2; third time, took a measurement from the other end of the deep end and still got FC 2.

 

[Richard320]

6/15 5 pm:
FC 4
CC 0.5

6/16 11 am
FC 2
CC 0

Did the test three times this morning first time, I put in r-0003 instead of 871; second time, I knocked the vial over after getting the FC reading of 2; third time, took a measurement from the other end of the deep end and still got FC 2.

Well, get a CYA reading, adjust your target FC to that, then add the right amount of bleach!

You'll be needing bleach pretty much daily.