You shouldn't assume the pH or ppms of your water is static. Mine can vary widely depending on seasonal conditions.first ask your municipality for a water analyst. it will tell you if they use chloramine or chlorine. if its chlorine then let it sit for 24 hours. air stones help keep water fresh and oxygenated AND help evaporate chlorine quicker. If your water does happen to contain chloramine, then look into RO water systems.
Even if you evaporate chlorine, you can still have a high ppm rating. Solution is getting a ppm meter. If you plan to get a meter i suggest one that does ph as well. Do some reading on where you want ppm's to be for different stages of plant life and in regards to nutrients.
Honestly though i find all that to be a lot of work. I dont have a meter for either ph or ppm. I just used a ph test kit a couple times to figure out how much ph down is needed for my tap water. for nutes and ppm - start with 1/4 strength and go from there.
Im a noob but i read through a lot of shit on here. I suggest you do the same. Most of the time when you have a question its on youtube too.