30 ppm drop in FC overnight?

[Xenon]

Back story here if needed:
http://www.troublefreepool.com/low-salt-and-chlorine-help-t35930.html

Todays test:
NaCl 3100
CYA 75
FC 0.1

So before I got to read advice from others on waiting to shock my pool (wknd vacation) I added about 1600 ozs of bleach to the pool last night around 9pm in a 2 hour process (cleaning cartridges, skimming, brushing and other things around the yard) in order to bring FC to 30ppm.

The water is noticably clearer today. It has been cloudy with no direct sun this am. I took water to pool shop at noon and got this 0.1 FC result. How can this be? Seems ridiculous. The guy at the store said there is a 10% chance that the test was "blanked out" by a high reading. So WHAT DO I DO? wait it out or add another 12+ gals of bleach? My test kit is in the mail.

Salt is now up to 3100 from 2100 yesterday but SWG has not kicked back in. The guy at the shop said "it definitely should be working by now." He also didn't seem to be a fan of liquid chlorine...

This all might be a little easier if I actually lived on site

 

[JohnT]

The pool store probably uses a test that bleached out at a higher level. Dilute your sample with 3 parts distilled water and retest. Multiply the result by 4.

 

[JasonLion]

Or use the OTO chlorine test, which can very reliably tell you if FC is near zero or not, even if it can't tell you just how high the FC level actually is.

 

[Xenon]

Well, my test kit came in today and my FC really is non-existent (after 13-14 gals). This drives me nuts. Could the bleach be ineffective? Could the pool be to hot (87F)? What would cause it when my CYA is 75-80?

Now that I'm leaving town for a couple of days should I add anything else to it? for the weekend or try to shock again & with an algal bloom when I get back?

My instant salinity test on my SWG is up to 2670, but mine and the pool house tests show about 3100, so it's not working efficiently if at all.

Really at a loss

 

[JasonLion]

Too hot has nothing to do with it. That isn't too hot. There is a small chance the bleach had lost it's strength, but that is extremely unlikely unless you bought it at a dollar store.

Shocking is a process, not something you do once and are done. You haven't finished shocking the pool. You need to bring the FC level back up to somewhere in the high 20s, and keep doing that until you can maintain an FC level overnight.

If the water was cloudy to start with it is not surprising that it used up that much chlorine. If you leave it alone now, algae will just start growing again and the chlorine you have used up to this point will be wasted.