Bestway3-in-1 Pool and Spa (Lay z Spa) Test Strips (50 strips) for Chlorine, PH and Alkalinity testing #58142

Has anyone bought these? I have and keep getting the same reading. Every time hottub is dipped. I previously bought Clearwater strips, they were ok.

After adding the normal amount of chlorine to new water, these indicate zero chlorine (impossible)- are they defective?

Can these test bromine as well

The photo shows that they are bestway brand, which was why I bought them. The ones that arrived are unbranded