Deep Water Hydroponics (the Ikea Way)





Introduction: Deep Water Hydroponics (the Ikea Way)

This is my first instructables (please go easy on me). I had a few pepper plants planted in regular compost and they seemed to be stalled... I planted them two months ago and they grew until a certain point and then they stopped. Even though they seem healty they look like little bonsai trees... :) So I decided to try something different. Let's see how it goes.

Step 1: What You Need:

Something to punch/drill 5mm holes
3 x Ikea TROFAST boxes (see pictures)
Air pump with tubes and airstones

Step 2:

The boxes don't quite fit together so you're gonna have to remove the little plastic thingies in the corners. It's extremely easy and fast with some pliers. (just rip it off)

Step 3: The Holes

Drill some 5mm holes in the bottom of the small boxes

Step 4:

Add something to hold your plants (I used expanded clay)

Step 5:

Give them oxygen by adding the air pump (I'm using a pump with 2 air ways) and airstones. The top bins are barely touching the water - the idea is that the roots "chase" after the water and grow as the water level slowly lowers. In the beginning it's important to check if the expanded clay touches the water so that the plants don't die on you. The expanded clay acts like a sponge and you will be surprised to see that even though your top containers are barely touching the water, the top clay balls get a little moist. I Added a timer so that the pump shutts off from time to time but when the roots get all submersed in the hydroponic solution I will probably bypass the timer so that the roots get oxygen 24/7.

Step 6: Give Them Food

Add your favourite nutrients to the water. I use a 3 part hydroponics solution from General Hydroponics (flora grow, micro and bloom). I usually let two 15 liters jugs of tap water resting outside for 3 days so that the chloride evaporates or dissipates (or whatever) and then mix the solution inside the jug one of the parts at the time.

Step 7: Check PH Level

Keep your hydroponics solution pH under control. I keep mine between 5.5 and 6.5. To tune the pH I add a few drops of lemon juice to a glass of water and then add that water gradually to the hydroponic solution until I'm happy with the value (lemon juice to lower the pH and baking soda to rise the pH level)

Step 8: 3 Weeks Later...

Update #1 - three weeks later they are looking good and strong. The bigger one is starting to flower witch means that hopefully there will be a pepper or two there very soon. ;)



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    Hi this looks very interesting. Is it necessary to use an air pump. Can't you just introduce a valve or two to allow natural air flow? Or isit a case of not allowing the water to remain stagnant?

    3 replies

    hi! you need to oxygenate the water in someway. the airpump is the easiest way to do it. You can add a timer so it's not on 24/7.

    Hi! :) nice work. Of course I don't mind if you share a Instructable with the community! :) I'm proud that I managed to inspire someone to actually make one. (your lettuces look good by the way. I tried my system with lettuces before and it worked just fine. You will be surprised how fast those babies will grow!)

    I'm not really a specialist but I think they are not mandatory, specially if your system is not airtight. Mine was not airtight (yet close) and the day my pump failed was the day my plants deliver their soul to plant heaven... maybe because I had 3 large plants fighting for air and nutrients in a near airtight container. the roots started to rot and i failed to bring them back to life. It was in the middle of the summer and here in Lisbon it can get insanely hot.. Heat + Black container + broken pump = perfect storm...

    BTW: I read somewhere that DWC without airstones work better with non fruiting plants.

    Therefore my advise is: buy a cheap pump just to stay on the safe side. they are pretty quiet and the power consumption is very low. if it bothers you, buy a timer so wit turns off from time to time.

    I've been looking for air stones where do you find yours?

    1 reply

    Hi! I bought my pump and the stones at a chinese store I have in my neighbourhood (this stores sell everything :) ) but you won't have any trouble finding a similar one at a pet shop. This kind of airstones are usualy used for aquariums.

    Deep water culture... try ebb and flow, you won't have all the problems of deep water.

    1 reply

    I have an ebb and flow system already. I'm just trying out new things. It's a learning process for me. :) What problems should I expect from DWC?

    so are the top bins IN the water or not?
    If not how do the plants get liquid as long as the roots havent grown through the holes?

    4 replies

    Hi! The top bins are barely touching the water(0.5 cm). The expanded clay once in contact with the water get wet and absorbs moisture from one to another - all the way to the top - and hopefully will stimulate root growth in the beginning. The plan is: as the water level slowly lowers, the roots will have follow (something like the kratky method). I'll keep a close eye on it in the beginning so that it doesn't dry out too much as the days are getting hot here in Portugal. I'll keep you guys posted.

    I found -when using clay balls- that they remain quite dry on the top.
    You are gambling on root growth being in line with evaporation. Better keep a close eye on it :-)

    There's already a little root peaking out from the hole. :)


    Read what the author said buddy

    Why would you shut of the air pump? Skip this step since there are no advantages to shutting it off. Air pump only use about 2-5watts.

    1 reply

    You are probably right. I connected it to the timer of my other hydroponics system (the one that shutts the water pump on and off every 15 minutes). Let's see how it goes and probably once the roots reach the water I'll bypass the timer and leave it on permanently. I will have to find a pump that's a little quieter than this one... It's not that loud but this little "buzzzzzz" drives me nuts... :)