Building a Rubbermaid Hydro Bubbler Unit - Cheap and Effective

Discussion in 'Hydroponics' started by MVP, Nov 4, 2007.

  1. MVP

    MVP Registered+

    Okay gang, here is a quick instructional thread on how to build a home made bubbler. I have seen friends use store bought units that are similar (google for Emily’s Garden). If you wanna see the concept, check out Greg Green's book "The Cannabis Grow Bible" where this idea is discussed as well.

    Getting started - first the parts list:

    (1) 10-gallon Rubbermaid Roughneck storage bin (Lowes $5.50)
    (1) ½ inch I.D. clear vinyl flexible tubing, 12” length (Lowes $0.50)
    (1) ½ inch plastic elbow (90 degree) for flexible pipe (hydro store $1.50)
    (1) rubber grommet for plastic elbow (hydro store $1.00)
    (6) net pots of your choosing – I used 6” square pots (hydro store $1.50 each)
    (1) aquarium air pump, dual output (Walmart $15.00)
    (2) aquarium air stones – 6” length (Walmart $1.60 each)
    (1) roll of aquarium tubing – 10’ length (Walmart $2.50)
    approximate cost ~ $38.20

    Tools needed:

    Utility knife (or jigsaw if you have one handy)
    ¼ ” drill bit
    ¾” drill bit

    We'll get going in a minute by building the base of the bubbler.

    To give you an idea of what is possible, I just completed a grow using 2 of these 6-pack units that yielded 4 oz of Black Domina in one unit (2 plants), and 3 oz of Blueberry in the other unit (3 plants) using a 400 watt HPS in a 4'x2' closet that was 6.5' tall.

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  2. MVP

    MVP Registered+

    Building the Base of the Bubbler

    To build the base it is quite simple. Basically you just need to make the water level indicator. Mark the tub with pen or the head of a nail. Drill a hole with the 3/4" bit in the very bottom of the tub where we will insert the grommet and then the 90 degree elbow.

    NOTE: double check (measure) your grommet to make sure the drill bit is the right size. Mine is a 3/4" bit but you want to make certain that yours doesn't leak, and sizes vary. If you have to choose a bit that's either a little too small, or a little too big, choose the smaller bit. Seems easy but its also an easy mistake to drill the wrong size hole and find yourself going back to Lowes to spend another 6 bucks to fix a screw up.

    Drill the hole as close to the bottom of the tub as possible. It's important so that you can view your nutrient level as it drops. It is also how you will be emptying your nute solution out of this when you do water changes.

    After drilling the hole, take the burrs off of the opening with the utility knife. Be gentle and don't enlarge the hole, just clean it up so that the grommet will fit snugly. Now install the grommet by applying a small amount of liquid soap on it and inserting in in the hole. It might take a few tries as it is a very tight fit, but you want it tight to prevent leaks.

    Next install the elbow through the grommet. Again it will fit very tightly so use soap to lube it up prior to installing. Finally measure and cut a length of the clear vinyl tubing, approximately 5 inches long and install it on the elbow fitting.

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  3. MVP

    MVP Registered+

    Construct the Bubbler Top

    Now you need to make the top of the bubbler, which means you make a template from your net pot, trace the pattern onto the lid of the Rubbermaid container, and cut the holes using either a utility knife or jigsaw.

    First, take your net pot and trace a pattern on a piece of scrap cardboard, then carefully cut it out using a pair of scissors or a utility knife. Once it is cut out place your net pot into the hole in the cardboard and check to make sure it is a good fit. It should fit snug so that it will keep light out of your reservoir.

    When you are satisfied with your template, lay out the patterns and trace them on the lid with a Sharpie or permanent marker.

    This is where you have to be careful. Ideally you have, or can borrow a jigsaw. It will make it much easier and safer to cut the holes for your net pots. If not then you will need to use a utility knife which can be dangerously sharp and it's easy to slip and hurt yourself.

    If you have a jigsaw drill a small pilot hole and insert your saw blade in this hole, then cut out along the the pattern you drew with your Sharpie. For those using a utility knife you will want to have a piece of wood or thick cardboard underneath the lid when cutting it. Slowly insert the blade into the lid along the Sharpie line, and while holding the utility knife at a slight angle slowly move the knife along the pattern. Repeat until all net pot holes are cut out of the top.

    Last you will need to drill two 1/4" holes in the top of the lid so that the air lines can be inserted into the reservoir.

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  4. Comatose

    Comatose Registered+

    Nice DIY tutorial. A little rep for you...

    I'm just about to start a new batch as soon as I get a little floor space for the container.
    Mine is a lot like yours, but I seemed to have forgotten a spot to check the water level. I'm sure I can add one with little effort.

    I just wanted to add to your tutorial here... You might want to consider adding a roll of duct tape to the list, to wrap the box after it is complete. My rubbermaid container let in a little light before I added a solid three layers of duct tape. Now she's pitch black on the inside. Anyways, not sure if you're having that problem, but I thought I'd mention it.

    Anyways, good luck using it to grow, and I'll be looking out for a grow log :) Good luck!
  5. MVP

    MVP Registered+

    Assemble the Air Pump and Air Stones

    Here you will need to take the air stones out of their packages and set them in a container of water to pre-soak for a half hour or so. While the stones are soaking, measure the length of run from your air pump to your bubbler unit by determining where you will locate your air pump. Keep in mind that air tubing is cheap and it is better to have it a bit too long than too short.

    Since you bought a dual feed air pump you will need to cut two air lines of approximately the same length. Place the air stones in the bubbler, one on each end of the tub. Take your measurements and cut the tubing, then attach the tubing to the air stones and then to the air pump. Put water in the tub, plug in the air pump and observe the system to make sure you have good bubbling from the air stones.

    Little Hint: MORE AIR = BETTER GROWTH.

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  6. MVP

    MVP Registered+

    Hey Comatose, thanks for stopping by and giving input.

    I'm lucky that I have pretty dark containers but taping them up will definitely help. When I do I will be using aluminum duct tape rather than traditional cloth duct tape as it blocks light with a single application. I will also add a couple of check valves - one for each air feed line - to keep the system from backflowing into my air pump and causing problems.

    I encourage anyone that has ideas or suggestions to post them here so that we can spread the info and learn from each others experiences and mistakes.

    MVP :jointsmile:
  7. Comatose

    Comatose Registered+

    Hey again. I had tried to find that aluminum duct tape, but gave up and had to go with the old fashioned stuff. I also have the check valves, they were cheap and I figured they would save me a headache if water backed up. The only other thing that is different in my setup is I have 2x12" airstones. I guess all that really means is that I'm spreading out the bubbles a little more, not that I'm pushing more air (I'm pretty sure we're using the same type of pump).
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  8. MVP

    MVP Registered+

    I found aluminum duct tape at Home Depot in the same area where they carry the sheet metal and HVAC air ducts. I used that roll on an automotive project but will pick up another roll soon.

    As far as air stones, the more bubbles the better IMO, I bought the largest ones that they had at Walmart.

    And another observation for those building a system - its better to go to Lowes or Home Depot and get the black vinyl air line tubing rather than clear vinyl stuff so that you don't end up with algae growth.
  9. MVP

    MVP Registered+

    Setting Up the Net Pots

    In this bubbler set up you'll use a wick in the bottom of the net pot to deliver moisture and nutrients to the newly transplanted cutting or seedling. Prepare the net pot by cutting 2 inch by 8 inch strips from an old cotton tshirt, placing the end of the wick strip in the bottom of the net pot. Add your growing medium (I use Hydroton - expanded clay pellets) on top of the wick, holding the end while you pour in the pellets or medium. Leave enough room a the top of the net pot to place your plant into the pot, on top of the wick, and then add the remaining Hydroton to stabilize and cover the plant's root cube or rockwool.

    Place your net pot in the bubbler and repeat until you have added all of your plants that you want into the net pots and bubbler. If you choose to leave some of the net pots empty, I suggest filling them with hydroton or taping them up. You do not want any light entering the reservoir or you will end up with contaminants and algae growth in your nutrient solution. I actually like to leave one or two spots open so that the plants have room to grow, and more importantly, I can remove a net pot to check pH and PPM a couple of times a day.

    Well my camera battery has died, so I will continue this in the next day or two when time allows. It's almost complete so this should be enough to get ya going. If you have questions post them to the thread and I'll do my best to answer them for you. It may take me a day or two but I will reply.

    Happy Hydro!

    MVP :jointsmile:

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    Last edited: Nov 4, 2007
  10. MVP

    MVP Registered+

    You'll need these too if you're gonna do hydro right...

    Not much time to update, but you'll want to start saving for these, or buy them up front if you have the funds:

    PPM/EC Meter - the one I use is by the Primo made by Hanna, approx $20 +/- off eBay

    PH/Temp Meter - the one here is a Hanna pHep, gives you pH and solution temp - approx $65 +/- off eBay

    Environment Monitor - this one has 2 zones, holds the min/max temp, and the min/max humidity for both zones, approx $25 from

    MVP :jointsmile:

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  11. wman44

    wman44 Registered+

    this is a good post but i just have one question regarding the wick.....
    does it do through the bottom of the pot and into the nutrient solution?
    and eventually do the roots grow into the solution as well?
  12. MVP

    MVP Registered+

    Wick Question / Answer

    The wick sits on the bottom of the net pot and transports moisture and nutrients up to the newly transplanted seedling or cutting until the roots grow enough. The wick itself will sit in the bottom of the pot, and the pot will end up sitting in the nute solution.

    Eventually the roots will grow down into the nute solution in the reservoir, but the wick's purpose is to make sure the seedling/cutting gets off to a good start and develops a strong root system.

    When running a bubbler like this (technically a deep water culture [ aka DWC ] system), you will want to have a root conditioner as a component of your nutrient solution to prevent root rot. Some people use a diluted hydrogen peroxide solution, others choose a solution from the local hydro shop.

    Thanks for asking the question, and keep them coming. That way I am unlikely to miss something I assume people know already.

    There is a bit more I need to develop for this thread, but that was a really good question.

    MVP :jointsmile:
  13. slumper89

    slumper89 Registered+

    hey thanks for that.. im getting ready to start my first hydro grow.. getting really fucking bored with soil.. anyways right on and keep on keepin on...:jointsmile:
  14. zerocool5878

    zerocool5878 Registered+

    ok i have a question about the wick. am i laying it like in the pic above and then fill it most of the way up and then fold it down and place my rockwool right ontop of the wick and then top it off so you cant see tthe wick. So in other words the wick would be sitting on the bottom of the pot and the other end up along the side going right under the cube? sorry i just wanna make sure i got this right
  15. MVP

    MVP Registered+

    Pics Included Too

    If a picture is worth 1000 words, this explanation will be a little over 3000 words.

    In summary, it sounds like you have it figured out. One end of wick on bottom of the pot. Fill with grow medium - hydroton in my pics. Other end of wick you set the lil one on top. Then fill around and a just enough on top to keep the light from reaching the rockwool (to prevent algae growth).

    Take a look at the pics and post back if you have questions or need help. Hopefully your babes will look better than the one in the last pic. Its not getting enough light since it is being shaded by a much larger plant... its a runt.

    MVP :jointsmile:

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  16. MVP

    MVP Registered+

    In regard to the amount of nutrient solution needed, I use 5 gallons of total solution. The net pots will sit down in the solution at least an inch or two, maybe more depending on the depth of the pots you choose. It is recommended that you allow the water level to vary up and down by an inch or two so that the developing root system will get occasional exposure to air.

    You can choose to use any nutrient solution you want. I chose an organic solution using the Botanicare products: Pure Blend Pro (Grow for veg, Bloom for Flower), along with Liquid Karma and Sweet. I use Dutch Master's Zone as a root conditioner to prevent root rot.

    I'm short on time so I'll post more with pics a little later on today or tomorrow...
  17. Goat

    Goat Registered+

    A coat of the new white spray paint for plastic (Krylon | Krylon® Fusion for Plastic®) on the outside helps maintain low water temps in the bucket (and reflect light).

    I drill a hole (1") in the base, and use spigots from home brewing (beer) buckets, attached to a hose, for EZ draining (see spigots: NORTHERN BREWER: Fermenters and Accessories). Rigged-up irrigation valves never held a seal, and leaked for me. These things are the right tool for the job.
    Last edited: Nov 7, 2007
  18. MVP

    MVP Registered+

    Goat has some good ideas here ^^^ although I have never had a problem with leaks myself. As always do what you believe is best for your level of expertise with DIY projects, and experiment a bit.... there is always a way to builder a better mousetrap (so to speak...)
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  19. Opie Yutts

    Opie Yutts Registered+

    MVP, Nice, real nice. Have some rep.

    If I may though, I've built quite a few of these bubblers in various configurations. I have learned that:

    - Polyester absorbs and wicks water better than cotton. You can buy a square yard of thick polyester (mostly) material for about $2.50 from most any place that sells fabric, like Walmart. That's quite a few wicks. You can also get more expensive professional wicking material from the hydro store. It's called capillary matting.
    - Even the colored plastic tubs that look opaque will let light shine through them. I recommend wrapping the entire box with foil duct tape, or good thick, expensive regular duct tape, or cheap duct tape and do two passes. A little light is OK, but try to keep it out.
    - For the lid, heres a real easy way: You get a quarter or half sheet of sturdy foam insulation, and cut holes in it with an exacto knife. Much, much easier than cutting in the hard plastic. It might just save you a little blood. 3/4" thick insulation is usually fine, but I get 1" since it's not that much more money. If you get white insulation this is best, because it will reflect light back up to the plants without having to cover it in mylar or a white material. You can trace around the lip of the net pot, then cut just a little smaller than the lip and the pot will fit down in the lid perfectly, with the lip sitting on the foam. Nice and tight and free from light leaks. Also the foam is really easy to sand. You might want to cut your hole ever so slightly smaller than you want, then make it nice and round and tidy with the sand paper (about 150 grit). It's much easier to take a little foam off than it is to put some back. Of course if you have a scroll saw like me, cutting the holes is extremely easy and tidy.
    - Your plants will grow big and fast if you get a bunch of air to the roots. Also this way you don't have to worry about root rot. You can do this several ways. Use a big air pump and put a shitload of air stones in there (actually air wands are much better), put a power head submersible pump in there (the one that injects air into the stream) and it will circulate the water, or make sure you design you box so that there is a few inches between the bottom of the net pot and the bottom of the reservoir (so that you can have some of your roots dangling in regular old air), or do some combination of 2 or 3 of those. Oxygen to the roots is the key.

    Perhaps it would help to confuse him if we were to run away more.
  20. Opie Yutts

    Opie Yutts Registered+

    Different strokes and all, but I can't stand that black air line. It is real stiff, and when it gets stretched out, like to go over an air nozzle, it just stays that shape and likes to kinda just fall off the nozzles after awhile. I got a big roll of supple, soft air tube from the aquarium supply section of a pet store. It's kinda clear, but translucent green, and stays soft forever. Algae is not a problem since it doesn't grow in air lines. It will stay on a nozzle forever, and remain nice and soft a long time.

    And check valves: I would not use these unless you have a big air pump. Especially on weaker pumps, they reduce the air flow considerably, like to half or less sometimes. Instead, I use a gravity valve: simply put your pump on a small shelf or something above your reservoir, and the water cannot get into it through the air hoses.

    I've got a bunch of em, but I'll try and shut up and let MVP do his thing.

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