SWCG output?

[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.