DIY Undercurrent DWC System (pics)

Discussion in 'Hydroponic Growing' started by Original Past, Aug 4, 2011.

  1. #1 Original Past, Aug 4, 2011
    Last edited by a moderator: Aug 4, 2011
    Hi all,

    In my search for the ultimate hydro system, I finally decided on a 4 site undercurrent DWC, to fit in the lower portion of my DR90 Twin tent. The reason I consider this the ultimate system, for me, is because I'm lazy and impatient. I wanted max growth rate, because I'm impatient. DWC bubble buckets would work fine, but didn't want the hassle of checking nutes and PH in 4-5 different bubble buckets. I would rather have them all share the same water so I can dose and monitor it all in one place. Finally, I wanted a controller bucket, so I can route a chiller, probes for the Bluelab unit, and a place to add/mix nutes before they hit the roots of my plants.

    The cost of purchasing a similar system ( ) seemed outrageous to me ($800), so I built my own! I tried to use as many of the same components as the original, where possible.

    My parts (and retail cost)

    -Pump is a 250 gph Danner ($60)
    -Air pump is an Alita -15 ($125)
    -Unseals (about $45, but I bought extras)
    -5x 3.5 gallon rectangle buckets with hinged lids (about $50, shipped plus a couple spares)
    -float valve ($15)
    -Water chiller, Current USA ($100, used from a reef shop)
    -Air stones - Sweetwater (awesome!) 8x 3"x1.5", and 1x 9"x1.5" - (about $50 shipped)
    -Misc air tube, and 2" PVC, cement, hardware (about $50)
    -Bluelab ph/temp/ppm meter $300.

    Ultimately, I spent about $400 on parts, to build my hydro system. $300 on a Really nice meter, and $100 on a used chiller. That's puts my investment cost at the same as buying just the hydro unit from Current Culture, but I also got a killer meter, and a chiller included for the price of just a pre-manufactured unit.

    Aside from being half the cost, I have the same water pump and air pump as the commercial brand. But I have premium Sweetwater airstones.

    I stuck to a nearly identical design as the commercial unit. However one thing I did differently is add the PVD tee in between the two far buckets, rather than behind them. This allowed me to fit the entire unit in my 36"x36" tent. It would have been nice to have a bit of extra space between that tee, and the controller bucket, but I made it all fit.

    In hindsight, what I'd do different is paint the buckets until they're opaque, because what I did was use reflective tape on the kids, but a bit of algae is growing on the inside walls at the water line of the buckets (where I didn't tape) Luckily, the combination of chiller, and excellent aeration prevents it from growing under the water line. Additionally, I'd re-route my airlines into the buckets, as their location makes me have to bend the tub around the net pots.

    Not shown in the photos, is my chiller, and a tall vertical 36" fan.

    Construction was straight forward, I used a hole saw to cut my holes in the buckets, and connected them with 2" PVC and unseals (pain in the ASS to work with, but they are solid, no leaks!).

    I think the system's pretty straight forward. If anyone has questions, I'd be glad to answer! Any suggestions on improvements would be greatly appreciated.

    Note, I have a PVC union connection from the pump to the controller bucket, and a ball valve so I can route a hose to the drain. In hindsight, I'd have just glued in a T, or a Y and a couple valves to permanently mount a drain hose. But the union works fine, aside from a bit of splashing when switching to the hose.

    PS: It works like an effing champ! Absolutely amazing! My lights are Blackstar LED 240w each. My cat was a huge help in assembling the system, eating the fan leaves I trim from my plants, and playing with rogue hydroton balls.

    Attached Files:

  2. So sick! I wanna build some links for the uni seals and buckets?

    Can't wait for updated photos!

    Please start a journal....I'm subbed if you do....thanks for sharing

  3. Thanks for the compliments, man! It works really well. I have a single autoflower in there now. Unfortunately, only one, because the rest of my seedlings were stunted. (Short Stuff replaced them, but a bit too late to sprout another batch. So I'm growing the one out while my mothers/clones are maturing ready. I think I'm just a couple weeks out from harvest, but I'll post a journal. It works amazingly well. PH is super stable, temps are stable. When this grow is over, I'll make a couple mods (to block light, and add tees to my airlines and double up the airstones (because the buckets fill with so many roots, not all of them are exposed to the bubbles)... but other than that, the thing is pretty dialed!

    Aquatic Eco-Systems: Aquarium Supplies - Uniseals®

    Aquatic Eco-Systems: Aquarium Supplies - Uniseals®

    Buckets (they are called EZ Stor, and can be found at multiple vendors)
    This link they're priced per 6 pack.
    3.5 gal Square EZ Stor Bucket Pail and lid,w/handle, 6 Pack - EZ Stor® Square Plastic Containers and Lids

    Any other questions, I'd be glad to answer, but it's pretty straight forward.
  4. One last large of a inline pump did you get? Your suppose to get one rated GPH for your system right?

    Was this information found some place?
  5. That's awesome bro. Gotta give props to all the Do-It-Yourself projects. I'm also interested to see how two 240w LED's perform with 4 plants. I did a similar setup but with a single 240w LED and it just wasn't enough power. If two works out well for you, i might buy another unit and be able to grow during the heat of summer. Good Luck Mate!

    Cute cat
  6. Hi guys! I bought the smallest Danner Mag Drive (aquarium/pond pump) external pump, which is 250 GPH. If I did it over again, I'd probably pick the 350 GPH version for $10 more. Only because how I connected the valve, pump, and controller bucket. I made a loop-to-loop with flexible PVC, which I know increased the head load significantly. That extra oomph would be useful. But the one I chose works fine.
  7. Regarding the LED lights, since I only have one (very short) autoflowering Onyx under the LEDs, now, I moved them both directly over the one plant. They seem to be working excellent. Unfortunately, I'm now wondering if two will be sufficient for four plant sites. There's only one way to find out, and I'll be doing that, soon. I'll document it with a journal.
  8. Thats a cool set up. I was also looking to pick up one of those UC system but they won't fit into the DR90. Nice to see you made your own and fit it.
  9. Sweet!! Looks good!

    I just built two similar systems!

    The veg under current system is using 3g buckets, like yours, only black.

    The bloom system is using 5 gallon round buckets.

    Its working very well and im getting close to doing a right up.

  10. The key to making this thing fit in the DR90 is where the tee fitting is. I placed it between the two buckets, rather than extending out around the back side, with 90s feeding it. This also doesn't leave much room for the pump feed hose, but I did a loop-ta-loop with it, and if seems to fit just fine. Now it fits like a glove!
    • Like Like x 1

  11. Hey Dusty, black buckets, if they are more light-proof would have been brilliant. I couldn't find them in low quantity for the size I wanted, unfortunately. I used some reflective mylar tape, on the bucket tops, but that didn't do any good. The Panda film is awesome, it's super reflective, and very much light-proof. Even for these intense LEDs.

    Are you using large diameter tubing to feed your water, too? What did you use as bulkheads?
  12. Black 2" pvc and uni seals

    Hmm 36x36 for 4 plants? One of mine is 36x36........
  13. #13 kryptickasserol, Sep 8, 2011
    Last edited by a moderator: Sep 8, 2011
    I love the design man! I'm actually in the process of building one of these myself, though my hydrostore only had 1.25" grommets, so I'm trying to find the hole saw size and size pvc that will fit in them. What size uniseal did you grab for the 2" pvc?

    I'm also using a Mag250 pump, which is the one they have listed under their specs for their 4 bucket system.

    Once this system is up, I will be using it in my grow (journal in the sig). Hope to see more progress on your end man!
  14. Nice Rig!! Have you though about moving the Controller outside the tent for more room and less heat? I am currently putting an RDWC 4 bucket system together and am wrapping my buckets with Reflectix.. Its cheap and should work pretty well for keeping light and heat out of the buckets (fingers crossed)

  15. Thanks Kryptick! It was fun to build, and design, for sure. The Uniseal I bought was for 2" PVC, and it used a 3" hole saw. If you have a harbor freight nearby, you can get a holesaw set for like $10. It isn't the best, but will do for drilling a few holes in buckets. My set also had one big enough to drill the holes for my netpots, too! Looks like 1.25" uniseals need a 2" holesaw. Looking forward to checking out your system! Have you thought about which air pump you're going to use? If I did it all over again, I'd probably upgrade the pump to the 350, then I wouldn't need a separate one for the chiller, and would drain better, too.

  16. Thanks Beachbound! By controller, do you mean the Bluelabs controller, or the controller bucket? I have thought about mounting the controller outside the tent, just to make it easy to monitor, but I love to get in there and look at it every, couple times a day anyways... The heat it puts off is negligible, compared to everything else in the tent. My air pump puts out much more heat. And the LEDs on the thing are green, specifically meant to be safe in a tent without interrupting the flowering cycle. Let's hope that's the case, otherwise, yes, I will move it outside.

  17. In my state, I can have up to 15 plants. 4 in bloom, 6 clones (two extra in case I lose a clone or two), which leaves me room for up to 5 mothers. Believe me, I'd love to have 36 SoG candlesticks in there, but I do have a strong interest in staying within the guidelines that the Department of Health put out, in support of our medical marijuana laws. Originally, I was going to put 6 buckets in there, and put the controller bucket outside the tent. But I prefer not to modify the tent. This way I can simply remove the empty hydro system, and try another method, if I so desire.

  18. I exchanged my 1-1/4" grommets and picked up some 2" Uniseals instead. Turns out that I had quite the aquatic environment facility not too far from the grow headquarters.

    In regard to air pump, I'm sticking with my Eco Air 4 for my buckets, and a Danner Mag250, which is what Current Culture's 4-piece system comes with.

    I have a question...I'm using a Tough Box from Home Depot as my epicenter. My problem is being able to connect PVC to each side of the res, through the bottom of the tent (though holes that I will cut in), and inserted to the middle of the bucket. The tough box is nearly as long as the tent is wide, so my buckets would have to go all the way in each corner for the PVC Pipe connection to go straight.

    So my question is, do you think I can just push he pvc pipes coming from the front of the control rez right into the tent? do you think having on the sides instead makes a difference?

  19. Yep the Controller Bucket is what I am going to do, with 1/2" feed and 3/4" return, and stack a res top off bucket on top of the controller bucket.

    I also just purchased the Danner Mag-Drive 250 pump. I am thinking that should give me enough water pressure without going over the top.

    And be careful with those green lights.. I have read so many posts about Green being safe, then someone jumps on that with "how it all depends on the shade of green"..?? Who know? So by all means, if you do keep the green lights in the tent, and dont have any problems, PLEASE POST HERE and give us all the info :D

  20. Do you mean that the buckets will essentially be pushed into the corners? The only issue with that, I see, would be how the plants grow, and will run into the sides of the tent, before filling up the middle area. I might be picturing it wrong. I bought a couple tough boxes, early in the process, to build a regular DWC. They are nice boxes, without a doubt.

    If you're pushing the PVC through the tent wall (after cutting holes, naturally), I'd suggest adding some PVC unions, so you can disconnect the inside portion from the outside portion (for maintenance, moving, etc.) Because once you slip the PVC into the Uniseals, it isn't coming back out very easily! (use hot soapy water, and soak the uniseals in the hot water for a minute before assembly)

    Hope that helps answer your question.

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