Tap water varies from system to system. Hard water contains many minerals and could interfere with your cleaner. My public water supply is fairly soft (>100 mg/l) and I have had no trouble using it for any chemical solutions. Check with your water supply - call the office where you pay your bill - and ask for the most recent chemical analysis of hardness minerals. If you explain to the water treatment operator what you are doing, s/he can probably get answers for you. There are some water supplies with high levels of iron and manganese, either of which can interfere. Most likely, your public water supply will be fine for your needs.
Judy in Kansas, who spent decades working with water supplies.