My second hydro run - 2 site RDWC in a 2x4... with an external reservoir!

Hey ILGM fam!

Following the completion of my first RDWC grow earlier this year, I’ve spent the last few months overhauling my setup to address the biggest issues I encountered namely: solution temperature, circulation, tent space and difficulty of performing a solution refresh (drain/refill)

Before I dive into the details, here are the specs and a couple photos of my “finalized” setup (quotes because I think I’ll always be tinkering). I got pretty much everything from PA Hydroponics, Amazon and the big orange hardware store.

Equipment

  • Tent: AC Infinity 2x4x6
  • Controller: AC Infinity Controller 69 Pro
  • Exhaust Fan: AC Infinity Cloudline PRO S4
  • Circ Fans: (2) AC Infinity Cloudray S6
  • Humidifier: 3L w/adjustable output from Amazon
  • Lights: AC Infinity Ionframe EVO3 + AC Infinity Ionbeam S16
  • Chiller: Active Aqua 1/0 HP
  • Circulation Pumps: Active Aqua 250
  • Drain Pump: 1/10 HP self-priming transfer pump
  • Air Pump: Active Aqua AAPA15L
  • Air Stones: 2" air stone balls
  • Plumbing: 3/4" supply soft lines, 3" PVC return
  • Other: 8 Gallon grow sites, 17 gallon reservoir (system “full” is about 16 gallons)

Grow Space
In my home office I have a small closet which fits a 2x4 tent perfectly. Last grow I struggled with solution temps so I was determined to position the reservoir and chiller outside of the tent… not to mention there isn’t space in the tent for that stuff lol. To accomplish this, I made a set of bulkhead plates out of some 1/16 aluminum to pass water/air lines through the tent wall with minimal light or atmospheric leaking. More on that later.

Anyways, here’s how it looks:


I gotta give my wife a shoutout here who had the idea to put a short curtain above the tent to hide the “clutter” up there, such as the ducting for the exhaust fan that runs up into my attic.

When redesigning my setup, I wanted to keep as much outside of the tent as possible. I think I achieved that quite well! Aside from the obvious stuff you see in the above pictures like the reservoir, chiller, and various pumps, the driver for the light, exhaust fan, a power strip and some other wiring are all sitting above the tent on a piece of 1/4" plywood I cut down to match the tent’s footprint (roofprint…?). Conveniently, an attic access is in this closet, which I cut a hole in and used an HVAC flange to connect the tent’s exhaust ducting.

Atop the tent:

I keep a few printouts taped to the white board next to my tent. One is a VPD chart with a baked-in leaf temperature offset for quick referencing, the other two I made for myself which are a nutrient mixing guide (by week/drain cycle) and a growth stages guide which covers things like ideal VPD, light distance, when to do nutrient refreshes, etc. No shame, I love the data!

Prior to settling everything into its place in my office, I decided to leak test the system out in my workshop and boy am I glad I did! Each bulkhead had a slow drip that I couldn’t fix for the life of me. I ultimately had enough with it and hit those babies with some aquarium silicone and to no surprise, that solved it. As an added bonus, these tests demanded testing out the drain system and calculating how much water I need to fill, all good stuff! As you can see in this photo, the cardboard is dry - that’s a good sign :slight_smile:

After adding 16 gallons of water with my circulation pump running, the water level was just below the net pot in each grow site. The waterfall effect also disturbs the water nicely, which will help the hydroton wick it up during the seedling stage. This is further aided by air stones that are positioned directly below the net pot (not seen in this photo):

The drain system is something I’m especially happy with. Both grow site buckets have a bulkhead on the bottom, which are then tee’d and behind a ball valve which leads to the drain pump. On the drain pump, I put a garden hose splitter on the intake side. One port has a barb hose adapter on it and goes to the drain line from the buckets; this line stays connected. The other port I connect a short hose to and use that to suck out the water that remains in bottom of each bucket due to the bulkhead flange height. This results in a darn near 100% drain of the system and take less than 10 minutes start to finish!

The Reservoir features (3) bulkheads: one to supply the circulation pump (center), and two on one of the “ends” of the tote to supply the chiller pump and as a return from the chiller. I decided to toss a couple air stones in the reservoir near the bulkhead that feeds the circulation pump because my air pump has 4 outlets so, why not use them all?

Here you see the plumbing from those bulkheads to the water chiller supply pump / return from the chiller. Also visible in this photo is a really perfectly sized boot tray I found at a local garden supply shop which will provide me a time buffer in case a leak does develop during system use. I have these “Govee” brand BlueTooth water sensors in this tray as well as within the tent which will emit an audible alarm and send a notification to my phone if water is detected. I use this around the house and they’re great!

The central bulkhead, the lowest point in the reservoir, feeds the circulation pump seen here:

Now for one detail that I am particularly jazzed about, the bulkhead plates I made for the tent wall. I made this out of 1/16 aluminum with holes sized appropriatley for the 3" PVC return pipe, and rubber grommets for the 3/4" water supply line and two smaller grommets for the air hose coming from the pump. I made two identical plates (one for the inside, one for the outside) and installed them with rivets.


Tadaaaaa!

Another fun little detail is this platform I made out of scrap for the humidifier to sit on, providing a pathway for the drain lines. I had originally placed the humidifier on the “roof” of the tent and used corrugated hosing to deliver the mist inside, but this yielded excessive condensation in the hose which ultimately became a puddle on the tent floor. So I had to come up with a solution to fit the humidifier inside the tent, and this was it.



Lastly, I made an adjustable trellis using PVC pipe, eye hooks, string and ratcheting hangers. I’ve never SCROG’d before so I’m excited to give it a try. Since the net is suspended by ratcheting hangers I can easily adjust the height to best suit how the plants grow. I intend to do a “two tier” scrog, and for the upper layer (which I understand is mainly to support colas) I’m using one of those elastic trellis nets that I will install during the flowering stretch. I covered the “top” of the screen in aluminum tape cause why not?


Phew, I think that pretty well covers it!

I had a lot of fun nerding out and building this setup, and am super eager to put it to use. I’m starting from seed again, and this time I’ve chosen to grow a strain from a local company called “Green Mountain Cheddar” (can you guess where I’m located?). It’s a feminized photoperiod indica that one of the guys at the local grow shop had nice things to say about, so I thought I’d give it a go.

I plan to germiniate seeds in the next few weeks, and you can be sure I’ll keep this thread updated along the way! If you made it this far, thanks a ton for reading!!

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I like it ROG approved…very nicely laid out and gives a good feeling when looking at your setup…one comment is 'have you always had that humidifier in the tent like your photo shows…I would think having it that close to your girls is going to increase the chance of mold…just a smoking thought

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Wow that’s a seriously impressive setup. :+1:t2:

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Very nice set up! Shows a lot of talent on your part and the wife also. I agree with @Retiredoldguy, have had problems with placement of a humidifier inside a small tent. A lot of cheaper humidifiers will not work well if the humidity is above 50%. The mist doesn’t dissipate well especially in a small area. This can result in the moisture collecting on the leaves and not letting them breathe.
AC Infinity has a small humidifier that can set outside the tent and the discharge can be piped into the tent. I bought one last spring, but have not used it yet. I think others here use this humidifier, maybe someone has firsthand experiences.

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Very cool. Always fun to see all the variations people devise on this theme.
So do I understand correctly that you’re using a standpipe of some sort for a top-skim drain?

A “Reptile Fogger” is what they’re called on Amazon. I’m still waiting to pull the trigger on one myself. An Inkbird humidity controller would be a good choice if no ACI 69 controller.

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Very impressive Grow Bro and appreciate the build details :muscle::muscle:. Nicely done and should grow some monsters :love_you_gesture:

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holy crud dude, that set up is freakin incredible :clap: .
im takin notes :memo:

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Talk about a impressive setup. Dude, you got it going on. Can’t wait to see where this leads.
Awesome work brother.

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Looking very good. I’m working on the final touches for my 4 bucket RDWC and plan to have it finished today.
I watching this thread. I like your system.

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I find it best to just use domes on my seedlings, and keep the tent at about 50%. Makes life much easier. Actually if the humidity is above 55% I don’t use domes as much nowadays.

I started replying individually… forgot about multi-quote feature… doh! I tried to edit my reply but missed the window… doh again! Sorry for double-reply :upside_down_face:

Thanks for the stamp of approval :smiley:
RE: humidifier – nope this whole setup is new, hasn’t been run yet!

I first tried putting the humidifier (reptile fogger) atop the tent and running hoses inside, but it created way too much condensation in the corrugated hoses which ended up all over the tent floor. I’m not sure where else to put it, but I can use the hoses to route the output away from the grow sites which I think would help mitigate mold risk. Thank you for the input!

Thanks Ickey! See my response re: the humidifier… I’m not sure what my best option is. This one is a reptile fogger from Amazon which included corrugated hoses, which without diving deep into the fundamentals of humidifiers, I figured was pretty similar overall to the AC Infinity unit. I may try positioning the humidifier atop the tent once more with a shorter discharge hose, maybe that will yield less condensation/spillage. Thanks for the input!

This is precisely what this unit is, a reptile fogger! I used the Inkbird controller on my last grow, connected to a mini humidifier and dehumidifier. Definitely did the job! I enjoy the “all-in-one” nature of the Controller 69 and how it enables me to monitor/adjust from my phone. For $100 I think it’s a pretty great value!

Big thanks Grow Bro :pray:

Haha thanks I appreciate it!!

Thank you!!

Thanks and hell ya! Speaking from experience, make sure to do a leak test somewhere you dont mind getting wet :sweat_smile: It was a little sketchy for a minute for me before I decided to move my leak test expeiment to my workshop haha

Yeah I like to germinate in a humidity dome and slowly crack the breathers once they sprout, then transplant the rooter into the hydroton once the tap root pokes through. I’ve not tried going dome-less :astonished:

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Here’s an idea. Use a small bucket, maybe a gallon, and put room temp water in it. Put an air stone in it. In that small of a space it should evaporate pretty easily and keep your humid at a good level.

I have read that with the AC Infinity humidifier setting on the floor outside the tent. Water will collect and run back down the discharge hose into the humidifier. I plan on keeping my hose on an incline through the tent, and let the end discharge behind a circulation fan. The AC Infinity humidifier comes with a humidity sensor, so it can control itself as a standalone unit. Also the AC Infinity tent comes with opening for the sensor and the discharge hose. I have been very impressed with their stuff.

Alright thanks to all the awesome community feedback I routed the humidifier output up and away from the plants, above where the circ fans

Seems like it will work! :metal:

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This is awesome setup, nice job!

I have a few comments on your hvac that may not be an issue, but something to keep an eye on. First, taking your make-up air from inside your home and exhausting to your attic may put your home under negative pressure. If so, can elevate your heating and cooling bills quite a bit. Next, I would be slightly concerned that your fan may struggle with the filter and all that duct with 90⁰ bends. If you run into trouble may have to go to 6". I have both 4 and 6" models and 4" doesn’t deal with static loads near as well as the 6". Last, make sure to set controller up to always run fan at minimum speed when lights are on. You don’t want to starve plants of co² just because temps or rh are a couple points low.

Best of luck, hope these turn out well for you!

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Great advice. I do have an answer to this because i few for three years with the same exhaust setup.

First, he should definitely upgrade to a 6 inch exhaust with a variable speed fan. The 90° bends won’t be an issue for him then.

Second, using the house as the lung room gives already temp controlled and usually humidity controlled air intake. It worked so well for my closet grow. Heat was never an issue.

Third, exhausting into the attic actually increases air flow and reduces temp in the summer and increases temp in the winter. In my experience my hvac cost was cheaper after i started growing.

This is all my experience and I’m no expert. :blush:

This wasn’t my experience. I never noticed any difference in the comfort level of my home during summer. I just associated that to the reason my cooling bill tripled. At this point I just thought my grow was really expensive to run. But in the winter I could feel cool drafts around windows and noticed my furnace cycling constantly. I did some asking around and the negative pressure was suggested by multiple people. I intalled diverters to keep exhaust in my home just going to a different room and both problems went away.

I know that not every situation is exactly the same, this is why i tried to say it can be an issue instead of being certain it will be an issue. Pulling 100⁰ air into a home set at 70⁰ isn’t going to make it more comfortable for most. If it does then it doesn’t need to be set at 70⁰ haha. But I agree that not everyone has 100⁰ summers or probably goes from having ac set at 70⁰ straight to having heat set at 70⁰ either.

Lol i guess I’m the odd one… I totally have 100° summers with 100% humidity and i have my indoors set to 73 year round.

We all have different experiences and the more we share the better we become.

Very true that every situation is unique, especially when it comes to geography, but it’s generally just never a good practice to exhaust moist air into an attic. in addition to those associated with negative pressures in the living environment, it can create all kinds of unwanted moisture problems in ceilings and roofs, especially in northern colder months.

For one example, it’d be no fun to find out 5 years later, that attic venting couldn’t handle the excess, and all that moisture was condensating on a bathroom or range exhaust tube, and only finding out when the ceiling started showing signs of water damage.

True in all aspects. I live just outside of Birmingham, Alabama. We use whole house attic fans here a lot. Geography is everything.

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