With 2 19 gallon plant totes and a 27 gallon main rez I’m thinking 20 gallons of nute solution will work wont it?
A typical RDWC system (which is what you are building) is normally connected between totes and rezervoir, near the bottom of each with a large bore PVC pipe. If you remember your Science Class; pour liquid into one and they will all level off at the same height. Place a submersible pump in the far tote, and the return into the rezervoir via chiller. You will get ample circulation. Run plenty of air.
Ok. In a RDWC do you ever chage reservoir or the water in the system? Doesn’t seem like you can if they are all the same height and connected. I’m sorry to be asking all these questions but it my maiden voyage into Hydro.
If there is never a solution change then I get it and it sounds simple that way. If the water has to be changed then I will need another pump to pump solution out for disposal and refill…
Not the best picture, but I have my totes sitting on top of milk crates to get them higher, for me to get under to trim. Reservoirs are same size as ones with plants. You will need a larger pump for your chiller. They tell what size you need. For the 1/4hp minimum of 400gph. The ones you have will work for recirc between rez and plants. I go with same size totes, but I know @peachfuzz runs a smaller rez. Maybe he can help you with what you have.
Oh yeah. You have to change your solution. I’ve got a lot of things I was going to say, but I can’t remember right now. I’ll remember tomorrow.
I may just go get 1 more 27 gal. I have 2 already.
@Grandaddy013
I just did alot of reading on Google. Damn it the ole internet cant be a little helpful. It gave me a better grasp of how to do it. The 1/10 hp chiller calls for 315 gph pump and mine are 291 gph… from what I see out there the next step up from mine is 330 gph so I’m gonna go ahead and try what I got. I’m gonna build my big setup out in my shop using 1 1/2 in pvc and unseals. This one I’m going to use bulkheads because it’s in a tent and not a large room I can expand in.
291 will work perfect for the chiller.
Try to add some type of drain system better than a pump that is in the reservoir. Also best to use submersible pumps as they have screens keeping foreign objects from breaking the impeller or jamming it which burns out motor.
A pump in the reservoir can only empty it down to about 2" deep then you have to get the rest out.
I personally just have a t in my res pump that has a shutoff. I have an extra 30’ 1/2 " line I add to t and open it to drain system as much as pump can do. I then use a cordless drill with a syphon system on it to drain the rest.
https://www.amazon.com/WaterAce-WA62UP-Submersible-Utility-Black/dp/B07FCFWGMP
You still have to drain, clean, disinfect and exchange nutrient solutions. Remember if nothing else the plant is taking in salts and expelling others so eventually you will have a bad concentration of the wrong stuff in your rez. Some folks add a drain, others (like me) just use an inexpensive pump and pump it out to allow access for cleaning/maintenance.
Something to consider too is: every time you poke a hole in a tote that’s a potential leak. This is all part of planning the perfect system for your situation.
In the veg room, I dip out totes with 5gal bucket, then wet vac. In flower room, there is a drain. I use a garden hose to siphon out most of it, and the wet vac to finish
@Grandaddy013 that’s awesome. I have a wet vac I’ll have to try that out later. Thanks for sharing !!!
As long as your “flow back” pipe is large enough, then water will find level instead of “flowing back” per say.
It’s when your “flow back” pipe is to small, and all these pumps in your reservoir pump water through your system faster than it can move back through your “flow back” pipe that you get in trouble.
@kettle
I like the waterfall effect you have going on. I am thinking I might want to set mine up that way. Ran across a couple vids on it today.
I used 2" on my last system. On this one I use 2. 1" pipes
one thing I do that I don’t regret and I know I never will from decades with aquariums, is using good quality bulkhead or through fittings… these are made in Australia im pretty sure… and some lube… no leaks… they come in all sizes but they are expensive… the 2 inch ones are over $25 AUD each… but they are so good… 
@kettle do you have a link to those ?
Are they abs?
I have been trying to find bigger than 1 inch for a future setup.
I think they are made from nylon, don’t buy them from Australia but they are here : https://www.irrigationwarehouse.com.au/category223_1.htm
these are the 2 inch ones I actually use
both are links to plumbing fittings… 
