Check you local water resource board via the net to see just what is in you tap water. While tap water isn't poison for plants, some city tap water has chloromines in it which isn't plant friendly and can't be aired out like chlorine can be. Also, if you can afford it, there are some reliable
water PH meters on Amazon which cost only $13. I would pass on those meters with two long metal spikes. They are worthless for measuring soil PH.
https://www.amazon.com/VANTAKOOL-Accuracy-Measurement-Household-Drinking/dp/B0789G7MVP/ref=sr_1_29?ie=UTF8&qid=1521676981&sr=8-29&keywords=ph+water+meters
You can buy
soil PH test kits where u put a bit of soil in a vial and add drops and compare to a colored test strip to determine soil ph.
If you find that your tap water contains chloromines, Tetra makes a product for aquariums called Aqua Safe. 10 drops per gallon is all that's needed to remove it. Chlorine can be removed by simply letting your water "gas out" in an open container for a day or two.
Hope this helps a little.
