After reading over this link, I combined several of the methods & added my own thing. My new RDWC system consisting of six 9 gallon modules (5gal buckets w cone tops that hold 10 inch netpot) running on 1200 gph EXTERNAL inline water pump with a 60 quart cooler as res. This is how I built in detail for anyone else wanting to run RDWC and say mother Fuck that chiller bullshit. If your like any normal grower, your around your garden once every three days at least.
1st thing was to go with a nice better than dollar store good sized well insulated cooler that has a drain. Got my 60 quart which rolls on wheels with a handle for $35 in the winter time. Probably cheaper now. I bought a few sheets of MDF board, couple hinges, some cheap window seal kits, couple sheets of board insulation, & screws. In short: I built a box from MDF that the cooler would sit in leaving 6 inches extra on all 4 sides and big enough to line all the way around cooler with insulation boarding, Then made the lid so it sat flush on top and sealed with weather stripping. The 6 inch gap allows coolers original lid to be propped open 3 inches where I have four 80mm computer fans set up in different directions blowing air over top of res. Inside the res I can put 6 frozen 1 liter bottles and at the bottom I have two 9" disc diffusers made for wastewater treatment plants ( got both for $20) these keep the DO supercharged. When shut and sealed & because my res is located in the closet of my grow room the one liter bottles will stay frozen for almost 3 days no bull shit.
2nd thing I did was run 3/4" black Poly hose to my pump. My 1200 gph pump then connects to my homemade from cheap PVC pipe one in 6 outlet water manifold all made from 3/4" PVC. Each bucket has it's 3/4" bulkhead intake up installed with a ball valve near the right under the lid of the net pot with a simple 90' elbow trimmed down on one end inside to create waterfall effect & keeping water from blasting into netpot. I did this because as you all know the waterfall effect is the best producer of DO in nature. At the bottom of each bucket I installed TWO 3/4" bulkheads connected to a Y piece running back to the res. I used two rather than buying more stuff that was different sized and not knowing how well it would drain. Both drains have ball valves to making dialing it in and removing one bucket from system simple.
3rd thing is every bit of 3/4" hose is covered with cheap pipe insulation. The stuff you can buy 40 ft of for $15 to wrap your pipes in the winter with heat tape. Plus all six 5 gallon buckets are wrapped in cheap hot water heater blanket fabric. Keeping everything insulated then covered with mylar to reflect, res and both 1000 watt ballast located outside of room not to mention the two heavy duty CPU computer heatsinks with 92mm fans I installed onto my external inline water pump (worried it was going to heat up my water) has me sitting easilt at 68'F with an air temperature of 78' using NO CHILLER! Just a little ingenuity. So thank you everyone in this thread for your input, this is what I've came up with. I've yet to see anything that resembles root rot and as long as I change out the frozen 1 liters every 3rd day it runs consistent.