Directly in the village Strelníky there is a popular swimming pool. Current information on opening hours, prices and water temperature can be found on the website of the village:
http://www.strelniky.sk/hlavne-menu/kupalisko/zakladne-informacie/
I found also this article in a newspaper:
https://mybystrica.sme.sk/c/20606257/kupalisko-vstrelnikoch-vyhladavaju-ludia-zdaleka.html
A video from the swimming pool in Strelníky: