For my first run in deep water culture, I am using a Current Culture XL 8 system. I am following all of their general recommendations, system add ons, nutrients, and feeding chart. I have a 60-gallon top-off reservoir and 1/4 hp water chiller added to the system.
Nice setup. I use to run just like it but I made my own.
I recommend you lower your ph down between 5.5 to 5.9 for veg. 6.2 /6.3 is for flowering. I have a new water chiller for sale. Used 3 months.
If you need any advice dont be afraid to ask. 400 ppm is an great starting point for hydro. Every week if your seeing good growth increase 100 ppm until you hit around 800 ppm. By that time they should be ready to go into flower. Cheers