I’ve been watering with rain water collected fro...

You could use either or , at the end of the day it matters what the PH is like you always want to correct it to the right PH for medium . I can see your medium is soil based on that information your PH should be anywhere from 6.5 - 6.8 in order to prevent any nutrient lock outs . If your unsure what your PH is your local hydroponics shop or amazon will have them pretty cheap as well you can get the general hydroponics test kids for like 8-12$ and this kit will help you keep your PH range in check as well as you could go a little fancier and get a PH pen these usually will have a digital read out and they are very accurate . They range in price anywhere from 20-100$ depending on the brand . In order to correct your PH you will need products such as PH up and PH down they are very cost effective as you only use drops at a time to adjust your PH because of their strength . Other then that both waters are pretty much the same , you might get different minerals in the rain water then you would the tap water but its pretty much the same except i might suggest leaving the tap water out with no nutrient solution in it for 2 days so the chlorine can evaporate . Your in good shape and well on your way to having some kick ass young ladies ! I hope this information helps you ! -Happy Growing!