Can everyone follow the flow of the re-circulation?
The external inline pump, to the left of the chiller, draws the water starting from the reservoir. Water goes from the reservoir, though the top green 2" pipes along the wall, through the tent, and between the buckets. Then it drops down and tee's the water to the buckets for the return. The water flows through the buckets on the way back through the bottom 2" green return pipe, which is below the feed pipe. Then it follows the wall back until it arrives at the water pump which pumps it into the chiller, and the out of the chiller back into the reservoir.
Couple notes:
Green pipe is 2" PVC
Red pipes are drain
Blue pipes are water feeds from the house
I plan on cutting the tent and running the pipes through. I'll modify anything to make it work just the way I want, so this doesn't bother me. Haven't decided for sure, but I'll probably use a bulkhead fitting with the tent holes clamped in between and a pipe passing through it.
The chiller I'm getting allows for nutrients to be run through it. I wasn't sure about going with a sealed system with a dedicated pump and coil, allowing for a less expensive chiller, or just using a single pump and a more expensive chiller. The later is what I chose.
The chiller will be a Hamilton 1/4 hp chiller
https://www.amazon.com/Hamilton-Technology-Aqua-Aquarium-Chiller/dp/B004LPMOTU/ref=cm_cr_pr_product_top?ie=UTF8
Note to the noobs: If you're going to get a chiller, there are two different kinds. One's that allow for nutrients to be run through it, and one's where you can't. The one's that you can't you have to use a dedicated pump and run hoses from the chiller to a copper coil that sits in the reservoir, and then back to the pump which pumps it through the chiller. This is a "sealed" system. The more expensive chillers are aquarium chillers that have titanium heat exchangers.
The water pump I'll be using is a Danner Supreme Mag-Drive 18 (1800 gph) run inline (outside of the reservoir). The reservoir is 55 gallons and the buckets are 13 gallons. I'll say 50 actual gallons in the res and 40 gallons combined in the buckets. The lines carry a few gallons, but its not a big enough system where the pipes are going to be negligible. I'll be running a 90 gallon RDWC.
I may go down to the Danner 1200 gph pump. I don't know if the 18 is overkill. I calculated it out once and came up with the 1800.
Feedback is always welcome. I know everyone's going to have their favorite brands, but I'm pretty happy with my choices. I probably won't change anything unless I get a consensus about how flawed one of the components is. But adjusting sizes of components to fine tune this grow room and not go overboard on anything is totally up for debate.
And thanks again for any feedback. I hope the visuals help some folks who are new to this.