This is exactly how I found it. I just mixed 3 gallons in my rez, roots are about 9 inches below the net pot. Reading this, I may mix one more gallon to get the soup level up to just below the net pot.I know, I just like to add info to old threads in the case a new grower stumbles upon this through a Google search. Seems to be one of the top questions new DWC growers ask. I never needed to ask that question because I bought buckets that came with instructions. I know a lot of people buy baskets and buckets and build thier own.
Also, in case anyone cares, my solution to the chiller issue is large ice bombs. I have my single DWC bucket (stealth grow) sitting in a 14 gallon tote and I fill it with about 3 gallons of water. I fill gallon milk jugs with water and freeze them. I don't use my freezer much ever, so I rotate out 4 1-gallon jugs and a few Gatorade bottles to keep the temps under control. 2 full gallons of ice will keep my temps in check for about 8 hours, then I'll rotate them out again. The only time I had an issue I was out of town, ice wasn't changed for about 48 hours. But usually I don't have to rotate my ice bombs out but in the morning, when I get home from work and before bed