Chlorine (test kit trouble?)

[65corvette]

My last time to write in was regarding not being able to keep my chlorine levels up. I finally came to the conclusion that the problem was low CYA level. I adjusted that and I am still having trouble.

I took a sample to the pool store yesterday (only because my CYA testing tube has disappeared so I can't check the level). This was their findings: FC=10 (s/b 1-5ppm) TC=10 CYA=80 TA=80 pH=7.7 He asked if I had just shocked the pool because the the level was so high.

When I did the chlorine test here (I have the TF-100) the level was 4 as it has been for several days even though I am adding 64-96oz. of bleach every other day.

Could there be a problem with the either the R-0870 powder or the R-0871 liquid? Thank you!

 

[frustratedpoolmom]

My last time to write in was regarding not being able to keep my chlorine levels up. I finally came to the conclusion that the problem was low CYA level. I adjusted that and I am still having trouble.

I took a sample to the pool store yesterday (only because my CYA testing tube has disappeared so I can't check the level). This was their findings: FC=10 (s/b 1-5ppm) TC=10 CYA=80 TA=80 pH=7.7 He asked if I had just shocked the pool because the the level was so high.

When I did the chlorine test here (I have the TF-100) the level was 4 as it has been for several days even though I am adding 64-96oz. of bleach every other day.

Could there be a problem with the either the R-0870 powder or the R-0871 liquid? Thank you!

How old is your kit and where do you store it?
What color is the powder?
What color is the liquid?

"FC=10 (s/b 1-5)" s/b 1-5 according to who?

If your CYA is 80 then your minimum FC is 6 and your target is 9. If you don't keep the FC above 6 at all times, then you will likely develop algae again. So 10 is good. If you allow your FC to drop too low, algae can take hold...you would see the FC dropping rather rapidly, your bleach additions will stay one step ahead of it for awhile but eventually I think you would start seeing green areas on your pebbletec.

I hope you find the tube but if not you can order a new tube- I would really trust your test results over any pool stores, any day.

 

[65corvette]

My test kit is about 6-7 months old. I did order more of both the powder and liquid so it's not even that old. The powder is white and the liquid is clear.

When I said that the FC should be between 1-5ppm, that is what the pool store said. They said my chlorine level was too high and recommended that I add a dechlorinating agent. I did not do that because I didn't think it was good advice. I trust your site much more!

So, I still have the dilemma of not being sure exactly what my chlorine level is. The pool store is saying it is too high, but when I tested it last night the reading was 4. I don't want to keep adding bleach if it is not necessary. Can't too much chlorine cause problems also? I have not had any algae though since I first starting using your site (prior to that it was a constant problem).

 

[JasonLion]

I would believe your tests over theirs almost every time. One way to confirm that your test is working is to measure the FC level, add bleach, wait 30 minutes and then measure the FC level again. If the FC level remains the same something is wrong, either your test isn't working or the bleach is bad. But the most likely outcome is that the FC level will go up by very close to the calculated amount.

 

[Butterfly]

Could you please post a full set of test # using your TF100 test kit?

If indeed your CYA is 80, you will need to maintain the higher FC levels ( 6 to 9-ish ) as FPM mentioned.

Remember, the pool store tests can very often be very wrong. You have the best kit available, so take advantage of it and post the test results. We'll help you figure out everything else :-D

 

[Guest]

even though I am adding 64-96oz. of bleach every other day.

Why? Also, what is your CC? When a water sample stands (one the drive to the pool store for example) changes in its chemistry can occur.
I would be very interested in seeing a FULL set of your own test results and also knowing what the store is using for testing (Taylor, LaMotte, or strips)

 

[65corvette]

Okay - I'm answering questions from a couple different replies.

I measured the FC level=2.5 added 100 oz. bleach and tested in 30 minutes and the FC=4.5 I would have thought that it would have been much higher. Problem?

Full set of results: FC=4.5 CC=0 TC=4.5 pH=7.5 TA=80 CYA=80 Borates=50 I store my test kit inside because I know it is not supposed to be too cold or hot.

I know it is summer and temps have risen which burns up more chlorine, but should I be having to add as much as I am every other day? Help!

 

[frustratedpoolmom]

Where are you buying the bleach, what brand? That should have raised you more than it did, I agree. So either the bleach is weak or you have organics consuming it as soon as you put it in, which would indicate that you need to shock.

So your target was 6... because your CYA is so high, your daily bleach additions - you want to target the higher number - in your case 9 - to allow some residual at the end of the day. If you target 6, which is your minimum, you won't be able to properly keep the organics at bay. You want to keep the FC above 6. So when this is all straightened out, your dosing target is 9, not 6.

The best way to tell what is happening with your pool right now is do an overnight FC test. Test the FC after sunset and 30 minutes after the last, if any, bleach addition. Record the result. In the morning before the sun hits the pool, early am if possible (6:30?) test the FC again, and compare the 2 results. If you lose more than 1ppm, then you have organics consuming the chlorine and you'll need to shock.

 

[PaulR]

I measured the FC level=2.5 added 100 oz. bleach and tested in 30 minutes and the FC=4.5 I would have thought that it would have been much higher. Problem?

The pool calculator says that's about right for 3% bleach. Some store-brand bleaches can be low like that (I had that problem once). If you're using a known-reliable brand then something else is going on.
--paulr