Looks great, yup we were getting 1.75 - 2.25 lbs a plant and that was in 13 gallon buckets. It was a pain having the roots clog up the 3" pvc all the time though in the RDWC we were running. Another problem we kept running into were runts. The fix for us was to run multiple plants in each spot so a runt wouldnt ruin a harvest. I was thinking about running those 27 gallon black totes from Costco but your cooler idea is nice. I run chillers to be safe but man, the coolers are worth the money I think. I'll still run at least a small chiller on each one though, not worth the risk IMHO. I bet those little micro chillers on Ebay that are good for like 12 gallon tanks would be perfect for these coolers, they only cost $86.
Great work by the way, keep it up!