Water circulation

Mods please move this to a more appropriate subforum if there is one.

I've seen mentioned in a couple of threads to add chemical, wait 10 minutes, and test. My pool is 18'x36' with an 8' deep end, approximately 25,000 gallons, and has two jets, a drain, and a single skimmer... that doesn't seem like it would be enough to effectively circulate and mix chemicals in only 10 minutes.

Asked this question because I shocked this evening, adding everything to the skimmer and tested approximately an hour later - and though my target was 16ppm (and I figure I should be within a couple ppm or better), the sample I took was 21.5ppm! I guess among other things, it illustrates I probably need to add chlorine to the skimmer more slowly, but I'm wondering how long chemicals should generally take to be evenly distributed through the pool.

I don't think we suggest only waiting ten minutes. I typically suggest a couple of hours at least.