Need shocking advice

[ElkPool]

While I've gotten pretty good at normal BBB maintenance, this past week was a first--I went away for a week with no one attending to my pool. I put a ton of bleach in it (over shock value) before leaving, in hopes that it would last the week, but no such luck. I currently must have a chlorine level of zero. Putting in the dippers of powder doesn't even turn the test pink at all.

The water in the pool looks perfectly clear, and the filter's been running nonstop.

I would really like to swim Sunday (it's now Friday evening). As best I can tell, my options are:

1) Shock the pool by putting in a ton of bleach. While I feel that this is probably the "right" answer, I am worried that this will keep the chlorine levels high enough over the next few days that it wouldn't be healthy to swim.

2) Shock the pool using Wal-mart stuff. While I have *always* tried to stick to BBB products, I just now bought two bags of HTH "Super Shock 'n Swim". Listed ingredients are calcium hypochlorite 52%, "other ingredients" 48%. The bag recommends using this product weekly. How harmful would it be to my pool to use it once? Would it have as good a shocking effect as all those bottles of bleach?

3) Put bleach in up to the normal recommended value and forget about it. Can I do this? If I add bleach, run a test tomorrow and find negligible combined chlorine, can I consider it "safe"?

Thanks in advance for any advice!

 

[frogabog]

Personally... I'd dose to max FC for your CYA level, perform a CC test, if that passes then do the OCLT and call it good if everything passes.

Going to 0 can't always mean a need to shock, your pool might have just lost the rest of the chlorine shortly before you tested. You don't really know. If no algae has bloomed yet your tests will tell you so.

 

[JasonLion]

How appropriate it is to use cal-hypo depends on your current CH level.

With the water clear, I would raise the FC level to the high end of the normal range in the early evening, give it a few hours to circulate, and then do an overnight FC loss test. If you lose chlorine overnight, it is time to shock.

 

[ElkPool]

Thanks for the advice. My test results indicate I should probably shock (even though the water looks, smells and feels fine), and my calcium hardness is well within the normal range, so I think this time I'm gonna use the Wal-Mart stuff.