Should I shock?

[Rob621]

Yesterday I had what I would consider my first "heavy swimload". 9 young kids and 5 adults for a pretty much all day swim event. By the end of the day water was slightly cloudy as I would expect but nothing too bad. Cleared up this morning. I did an over night FC loss test last night and it dropped by about 1.0 to 1.5 ppm overnight. Is this normal given this load or should I shock it? I have yet to shock my pool as I am a new owner (although the PB shocked it when opening it this year).

Part 2 of the question, if I do need to shock I will likely use bags of shock provided by the PB since I have them. I chlorinate with bleach, but since I have the shock bags, seems easier than a bunch of jugs of bleach. Would I just throw this directly into the pool, dump it in a skimmer or what? Also with the bags is it a once and done process or do I still monitor the FC level to keep it at shock level as indicated in Pool School?

Thanks for helping a rookie out,
Rob

 

[JasonLion]

As long as the FC level never went down to zero, and you add some extra chlorine today (FC level perhaps 3 or 4 higher than normal) you won't need to shock. A large swim party puts lots of organic debris (shed skin cells, dirt, etc) into the water, which take a little while for the chlorine to break down.

The pros and cons of using the granular shock depend both on which particular kind you have (dichlor, cal-hypo, trichlor, lithium-hypo) and what your current levels are. Dichlor and trichlor add extra CYA, while cal-hypo adds extra CH. Depending on your current levels, you may or may not want to add those to the pool.