SWCG output?

[Looony2nz]

Hi -
Pool is 10,560 gallons. Have only had to add some acid (and the chlorine) up until this point.
Just yesterday, in addition to finding out the chlorine is still zero, we JUST added some alkaline increaser (baking soda equivalent) as the alkalinity was off a bit. Is this a result of no chlorine being produced?

Otherwise, no, even last week, when the TC,FC & CC was 0, we hadn't added anything else besides acid and chlorine, everything was fine for a two weeks. The pool has only been running for 3 weeks, 8 hours a day on the pump/filter - water is crystal clear.

[Looony2nz]

have not added anything else and it is 10,560 gallons

[Simmons99]

This may be a stupid question, but what are you testing with? I have heard from others that a high Clorine level can bleach the test so that you think it is zero. Is it a drop test that will register more than 5?

[Looony2nz]

yes, I am sure it is a high quality drop test. (pool stores) but 3 different places couldn't all be wrong.

[waterbear]

Many pool stores use the Talor Water Lab or the LaMotte Waterlink. Both of these use the DPD test for FC and TC and both can bleach out with high levels of chlorine. These are not the same as the FAS-DPD titration tests for chlorine. Many test strips also bleach out with high chlorine levels...depends on the reagent that they use.

My suggestion would be to get a cheap OTO test kit (color turns yellow in the presence of chlorine) at walmart or some place like that. An OTO/pH kit can usually be had for about $5 or $6 dollars. Test the water and see if you get a reading. Post the results. IF the color on the OTO test turns dark yellow, orange, or brownish it means that your cholrine levels are VERY high and that will make a DPD test bleach out and show 0 ppm FC and TC!

[Looony2nz]

I see your point, however, we added 1/2 gallon of chlorine day before when this was an issue and now chlorine (yesterday) was at 3. so...?if it was truly sky high and was "bleaching out", then when we added the chlorine, it would just continue to show as 0.
It now reads as 3. (store test).
The aquarite tech is supposed to be out this week....I'll let ya know what happens. Actually, its just a tech from the PB, as we called Goldline and they said they can send someone out, but if its chemical related, they'll charge us.