I know people like to spend mad money on hydro nutes, and I'm here to tell you, you don't need to! My very first grow was in DWC. I decided right up front, the KISS principle was the way to go. I decided on General Hy6droponics Maxigrow and Maxibloom for nutes, Cost me $15.85 each for 2.2 pounds bags ( they're dry nutes ). I've got enough left to grow at least 4 more grows, probably more. did they work? Hows a 6oz. dry Auto White Widow harvest sound for a first time?
As to ph, people fuss WAY too much about it. I ph my water and let it set for a few minutes, then add my nutes. Adding the nutrients drops the ph about another .1 so I ph my water no lower than 5.9 usually. Even then, I'm not too fussy about it. 5.8 to 6.1, I'm good to go. vI check PH on the fourth day and adjust if necessary. Ph will always rise, and contrary to what many believe, that’s not a bad thing. Look at a PH to nutrient chart. Not all minerals, etc are absorbed best at the same ph level. So keep your ph between 5.8 and 6.4 over the course of a week ( I change the res usually once a week ).
The ph change after adding nutes will vary depending on what you use, so its a good idea to test the res after a 15 minute wait to see how much it has changed because of the nutes.
Feeding Schedule:
I took my que on feeding from Hygro Hybrod on youtube. that dude is THE MAN when it comes to DWC. He grows single, one pound plus plants consistently. He sets his ppms at 600-650ppms thru the entire grow. Why? As he said, you can pour all the nutes you want into the res, it doesn't mean your plant can use them any faster, you can't force feed them and high EC or ppm levels can actually be toxic to them. During Veg, your plant might lower the ppms by 200 points in a week, so no need to add more, but its good to test until you know your plants. In flower, they can at time suck up 150-200 ppms in a day! If that happens, just top off the res with more nute/water to raise the ppms close to the 600 ppm mark again.
You can add any supplements you want, but keep the ppms in the 600-650 range just the same. I personally don't feel that all that extra stuff is all that effective. Its like fishing lures. Fishing lures are brightly colored and sparkly to catch fishermen....lol!
Ok. well that's just my way of thinking and doing. There are many other ways that work just as well, its all in how you want to operate your system.