Revision history [back]
Hi Trish,
This test strip works in the range you're asking about: https://www.sensafe.com/test-strips/sensafe-ultra-low-total-chlorine-30-pkts-of-1/
You might also consider a low range color disk test kit, such as this one from Hach: https://www.hach.com/free-chlorine-color-disc-test-kit-model-cn-66f/product?id=7640219520&callback=pf