I have to disagree with the two above posts. 75 is the highest you want your water temps to go, anything above that and you are risking bacteria. Also, ideal pH for hydro is 5.8, not 6.8. I believe the orange balls he's talking about is hydroton.

Follow directions on the nute bottle, if its the first time giving them nutes, use 1/4 strength to see how they react (so you don't get nute burn). Let them mix in your buckets for about 30 mins to an hour before you start adding pH up. I usually like to get mine to 5.6 and let it drift to 6.0 (giving me an average pH of 5.8). If you don't have one already, a pH pen is necessary, and a EC/TDS pen is highly recommended. Check out Hanna and Milwaukee for those.