DWC with Foam Rafts in 5 gallon buckets?

Discussion in 'Hydroponics / Aeroponics' started by Michael Huntherz, Jun 10, 2018.

    Michael Huntherz

    Michael Huntherz Well-Known Member

    I know some large scale commercial agriculture ops use DWC on big styro rafts, has anyone tried this on a smaller scale wih cannabis?

    I have an idea for doing it using 5 gallon buckets, but I am interested in hearing anyone’s experience with this method.

    It seems like literally nobody in the cannabis game is doing it, and I want to know if I am missing some major reason I should avoid it.

    Last edited: Jun 10, 2018
    Beachwalker likes this.
    Michael Huntherz

    Michael Huntherz Well-Known Member

    Thanks for the input everyone, it really helped. :roll:

    I am pretty fucking stoked on this idea, some of you fabulous bitches gotta know something about it. @ttystikk? @Cold$moke? @HydroRed?

    Other hydro wonks surely have some input, too. I know I am being impatient, I was born this way.
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    Beachwalker Well-Known Member

    I don't have any real input just following along, I can add that I've heard that people used to put plants in styrofoam and float them in the swamps ? That's where I got the idea to use crushed styrofoam as a medium at some point apparently, I don't really remember it but I still have remnants of it in with my grow stuff that I packed away from the 80s and 90s

    I think I mixed it with volcanic rock, I don't remember anything specific about it but I think it worked okay, I think the drawback was it used to float to the top, kind of like the perlite in soil affect ? I understand you're talking about using it more like the floating the plants in the swamp example and that's very interesting, I don't see why it wouldn't work ?
    - good luck if you try it!
    Michael Huntherz likes this.
    redi jedi

    redi jedi Well-Known Member

    Works well for things like lettuce or anything with a low center of gravity...not so well for top heavy cannabis.

    Cold$moke Well-Known Member

    Haha i got strawberrys in a dwc raft outside :)

    Although they where fresh crowns so they haven't taken off yet
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    Michael Huntherz

    Michael Huntherz Well-Known Member

    I have plans, will share them after a few more passes at the “design” if it can be called that.
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    Michael Huntherz

    Michael Huntherz Well-Known Member

    Good observation. I think have a plan to deal with that problem, pvc struts inside the bucket, tight tolerances, 2” thick foam and a cover lid with a hole in it. Zero media except a rockwool starter plug for getting the clone going. May build a medialess cloner, may not.
    ttystikk likes this.
    redi jedi

    redi jedi Well-Known Member

    Whats wrong with a net pot? They make ones that are flanged for a 5gal bucket?
    Michael Huntherz likes this.

    Larry3215 Well-Known Member

    Im no expert for sure, but I have two observations/comments.

    In traditional RDWC - in fact in virtually all types of hydro that we do - the roots are never 100% under water. There is always some balance between the roots having some portion exposed to the air and some portion constantly in the water. In aeroponics, ther is almost no portion of the roots under water. In DWC, a large portion is under water and in E/F the roots go from under to exposed on a schedule. One commonality - the roots that are exposed to the air are damp. Its that thinly coated portion of the roots that have the best DO absorption - assuming they are exposed to fresh air.

    1) The roots in your setup will always be under water - no air exposure. That means you must be 100% sure the water has max DO at all times, because the roots wont have any exposed, damp, thinly coated surfaces to directly absorb O2 from the air. That thin water layer on the roots is where a huge % of the O2 the plants use comes from. Thin water layers will come up to max DO very very rapidly and can stay at full concentration easily. With a thick layer of water, only the surface portions exposed to the air can refresh the lost O2 - and it takes time for the freshly dissolved O2 to travel down into the solution away from the surface. Its much faster to refresh the surface area that is exposed to the air than to wait for the dissolved O2 to travel through the solution on its own.

    2) Your foam raft will cover essentially all the water surface in the bucket. Its the constant refreshing of that surface that is responsible for most of the DO. The bubbles dont do as much oxygenating as people think - by a lot. Its the interaction of the waters surface with the air - plus, and as important - the constant refreshing of that surface with water from below. It is much more the bubbles lifting water from below and causing a roiling of the surface that increases DO - not the bubbles themselves. I think you will almost certainly need some additional way to increase DO.

    HydroRed Well-Known Member

    No experience with it personally, but have seen it attempted in a thread on here somewhere. IIRC the poster never made it into flower but in defense of the method, it was rigged up poorly.
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    Airwalker16 Well-Known Member

    I've done it. Light leaks and dirt. Use a lid.
    Michael Huntherz likes this.

    Cold$moke Well-Known Member

    I think it would work just fine if you

    Just set some kind of pot "in" the raft

    That way half the pot is up in the air and the other below the foam into the swamp.

    Use something like promix with a slow release fert like botanicare pellets.

    A few years ago i would have belied the whole
    Roots cant grow into stagnate water

    False lol they gave a will to survive :)

    Hence why kratky method works. (Still testing it with mj)
    Michael Huntherz likes this.

    Keesje Well-Known Member

    I have seen several grows where they use rafts or styrofoam boards, but never with DWC.
    The rafts sometimes have a hump, and the plant is somehow fixed in a opening in this hump.
    The bottom of the raft has some hollow space where the hump is.
    Like a big air bubble.

    Commerical growers use venturi to agitate the water or just circulation now and then.
    They also don't care if light hits the water. Neither do they care much about temperature control.
    I have never seen it with higher plants.
    And personally I would think it would give a lot of problems.
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    Michael Huntherz

    Michael Huntherz Well-Known Member

    Great thoughts, thanks for the input, seriously. I will work up a prototype and post it here for review. Net pots and hydroton are fine, really, may end up going that route if it turns out to be simpler than getting the raft right. Would really like to minimize or eliminate grow media where possible, without resorting to more power-dependent techniques.
    ttystikk likes this.

    rkymtnman Well-Known Member

    have you ever seen Heath Robinson's flooded tube grows? google it. he kills it with just a single 600 in a stadium grow. and no media, just a cube in the tube.
    Michael Huntherz likes this.
    Michael Huntherz

    Michael Huntherz Well-Known Member

    Nope, nice tip, I will check it out! Exploring medialess approaches for sure.
    I ran a single 600 for the last couple of years
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    ttystikk Well-Known Member

    The high plant count is a nonstarter in his state.
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    ttystikk Well-Known Member

    SIPS (sub irrigated pot system) might be worth looking at. There are some threads around here...
    Michael Huntherz likes this.

    Keesje Well-Known Member

    I think the most simple but high rewarding system I have seen on this forum is in the thread of KLX.

    Of couse also here you still need a pump and a timer, but that's about it concerning technics.
    He does it with a SOG, but it can also be used with less plants per square feet.
    Michael Huntherz likes this.
    Michael Huntherz

    Michael Huntherz Well-Known Member

    That’s a cool method, I have checked that thread out before.

    The stadium style flooded tube grow was amazing, but yeah that’s a scary plant count for my area. I like to keep it below 25 among all stages. I think I may even go down to two plants per meter and veg longer. DWC might be a real good solution for me, rafts or not.

    I really like aeroponics, but the plants aren’t portable once they have some size on them, which is a buzzkill for me. I should probably just bite the bullet and buy a bunch of netpots and deal with recycling some hydroton and breaking some plastic.

    I honestly don’t think DO will be a problem with the raft method. Using big airstones in each bucket and an air pump designed for a 60-100 gallon aquaria I am pretty sure I can aerate <=20 gallons of water adequately, even at warmer temperatures. I keep my fish happy, and I think they have higher DO requirements than roots.

    I guess the raft method speaks to my iconoclastic streak. I like bucking the status quo, I was born this way. I also have a hunch that it will kick a lot of ass if I can get it dialed in. I am firmly on the fence now, and I have about a week before I need to move the clones to their next stage. I must cogitate further.
    Last edited: Jun 12, 2018

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