Strange Chlorine readings..Help!

[Andrew]

I tested my pool water today using the TF 100 test kit (which is great). I have an inground 18x36 vinyl lined pool. My readings are:

PH 7.3
T/A 150
CH 200
CYA 100 (High)
Temp 84

My problem is the chlorine test. The cheap drop test shows an Orange color. Off the chart! But my TF100 kit which usually tests very well went like this: I added the R870 powder to my water sample and instead of turning red as usual it just stayed clear. Is this 0 FC?? Then I added a few drops of R003 and the sample turns yellow! Even if I retest and add a few drops of R871 in between, the result is the same. What gives?? I know my chlorine level is high due to the cheapo test and when testing my T/A the sample water goes from blue to yellow instead of green to red. I realize my CYA is high so I've been keeping my FC level high using liquid bleach. My pool water is crystal clear with a very slight trace of algea on the bottom. No chlorine smell or irritation. It hasn't rained here in New York for two months. What's my next step??? Any help is appreciated!

 

[lborne]

You have zero chlorine. Per the instructions, when you add R-870 powder, the water will turn red if chlorine is present. It might briefly turn red and go to clear, in which case you add more powder. But if it never goes red, you've got zero chlorine.

Visible algae means you are consuming large amounts of chlorine.

Get your CYA down by replacing some water, then shock and perform the overnight CL loss tests per pool school.

 

[duraleigh]

The cheap drop test shows an Orange color.

lborne might be right but I believe that OTO (cheap) test to be a good indicator of high chlorine. I believe it flashed and you missed it.....easy to do

Do the test again and this time add two scoops of powder one at a time and observe carefully. If it flashes pink as you add, you must add more powder to make it stay pink.

Don't add more than three....if it doesn't turn by three, something else is wrong.

 

[Andrew]

Redid my chlorine test today. The first scoop of powder turned red immediately and stayed as usual. Why would that happen today and not yesterday? My reading was high as expected, 18ppm. My big question and constant problem is the algea. How could I possibly have algea with that high of a chlorine reading? If I use more bleach it usually takes care of it for a while but I can't believe I need to add MORE chlorine at this level. What do you think???

 

[frustratedpoolmom]

Why do you think it's algae? You sure its not dead algae/dust/dirt/pollen collecting on the bottom?

You should do an overnight FC loss test. If the FC holds overnight and the CC is .5 or less, and you are still seeing the stuff on the bottom of the pool then it's probably not algae you are seeing.

Have you considered water replacement to lower the CYA level?

 

[Dale.s]

Redid my chlorine test today. The first scoop of powder turned red immediately and stayed as usual. Why would that happen today and not yesterday? My reading was high as expected, 18ppm. My big question and constant problem is the algea. How could I possibly have algea with that high of a chlorine reading? If I use more bleach it usually takes care of it for a while but I can't believe I need to add MORE chlorine at this level. What do you think???

I'm on my iPhone so I can't look up exact numbers but from memory shock level for 100 cya is 40 or so ppm, now remember that the test only goes to 100 for cya, it could be 200, 300 no way know for sure until you test. Your high fc may accually be way to low!

To get your real cya number mix half pool water and half tap, then test cya, double that number. Once you know you will have to drain and refill to bring it down to number that will help and not hinder your results.

 

[Bama Rambler]

Redid my chlorine test today. The first scoop of powder turned red immediately and stayed as usual. Why would that happen today and not yesterday? My reading was high as expected, 18ppm.

I can't help you with why it happened but I can provide you with a "you're not alone" story. It happened to me once a few months back. I still don't know why it happened but I rinsed everything out and got a new sample and it worked the next time just as yours did.

 

[zea3]

Redid my chlorine test today. The first scoop of powder turned red immediately and stayed as usual. Why would that happen today and not yesterday? My reading was high as expected, 18ppm. My big question and constant problem is the algea. How could I possibly have algea with that high of a chlorine reading? If I use more bleach it usually takes care of it for a while but I can't believe I need to add MORE chlorine at this level. What do you think???

If as Duraleigh said, the FC was so high it required 2 scoops of powder to stay red the day before, then the FC level dropped enough that the next day you only needed 1 scoop. You really need to know just how high that CYA is before you can complete the shock process. I think you have been adding enough FC to keep the algae knocked back, but the first time you miss a dose it starts to appear again.

Try testing CYA with the dilution method and see what the result is.

 

[Andrew]

Thanks everyone for your input, it really helps. The end of the pool season is coming around here in New York so I will just survive for another week or two and then close up my pool. Can't wait until next year to continue my BBB method. Have a great winter!!!