I don’t know why so many people are either unaware of, or actually think pH is not important. It is one of the biggest things that will affect the way your plant grows, as it has a very significant direct impact on the ability of a plant to uptake nutrients.
If you look in the very common General Hydroponics chart, below, that comes with their pH up and down kit, you can see how pH will change how available certain nutrients are at different pH levels, and you’ll notice the sweet spot for hydro is about 5.8, and much below 5.4 or above about 6.2 and things can become unavailable real quick, and that will starve your plants of those very needed nutrients which will obviously prevent them from growing well.
Also, absolutely water temperature is very important in hydroponics, it can mean the difference between healthy roots that thrive and root rot, as temps much above 72*F and dissolved oxygen levels drop significantly. People always think plants need CO2, and this is true at the leaves above ground, but just like you don’t want light getting to the roots, CO2 is not needed at the roots, and actually the opposite is true, they need oxygen at the roots.
As far as using your home water, I just recently wrote a very detailed response on what type of water to use, and why, here:
~MacG