Although TFP is not a medical advice site. You are next to a large source of water, the pool. Did you wash off the splashed water acid mix from your arm? Are you having any reaction now, after the fact? In a 5 gallon bucket with water, adding the dry acid and getting it splashed onto you, since it hasn't mixed yet to become full strength, right? Rinse it off, in my non-medical opinion, you are fine. But only you will really know.