I use the water out of the tap but I do run it through a RV filter. The city water here can be complete and total crap. The people that work at our water plant are scary ass stupid. I keep my water inside with the grow and refill as needed.
ROLS for over 10 years on this hill. Use mostly rainwater except for germination and first one or two waterings which are bottom watered with municipal treated tap. A tap water 5 gallon bucket left outside will have midges in about 4 days, not too lethal.
I add a tiny amount of vitamin C powder in the water and let it sit overnight. I run my drinking water through a filter, there's always microplastics stuck in the mesh.