One Part Nutrients

So i have in the past used Botanicare CNS17 and it was ok but PH was unstable and i always thought my buddy using Pure Blend Pro had way better nutes then me but he paid $50 a gallon while I paid $25. But at the time i was growing tomatoes and peppers, brussel sprouts, eggplant and the like. Now I really want to use a one part nutrient and i found the pure blend pro for $36.95 a gallon plus the site has a deal running for 10% off at the moment. So that makes up a good portion of the price from the cns17 . Does Anyone have an opinion or experience with pure blend pro? I would really love some input before i purchase. Thanks

Also my water is hard as fuck, Comes out the tap at like 550 ppm and a ph of 8.5 would i be better off using a nutrient specifically made for hard water and if so any specific recommendations on a one part nute for hard water? Also while i one part nute i would like to use Gravity in flower as per a friends recommendations.

use distilled water its like 98 cents per gallon

Well I'm a cheaP ass nigga. Plus i really don't wanna be buying a cart full of water every time i go to the store. [But my inner nigga just reminded me i can buy it with food stamps, lol]

40 gallons in my res. I could't do the one gal at a time, GH micro for hard water works pretty good ---Pretty damn sure you and me are in the same area cause thats how hard my water comes out-exactly. 550 and 8.5