Recirculating Hydroponics




About: Working my dream job in the Telecom industry, so chances are, i'll never have time to respond to comments or messages, nothing personal.

This unit allows for long term growth of large plants. There have been several hydroponic posts here in the past, but they all shared the limitations of either small plants or short term growth. This unit can grow a large plant practically indefinitely.

Step 1: Parts

You will need

Two stackable containers
A small fountain pump
1/2 inch pvc pipe , two elbow fittings, a threaded end cap and plug.
Clear vinyl tubing to fit your pump
zip tie
plastic window screening
hole saw and drill

and anything i forgot.

Step 2: The Containers

Primarily, you'll need two qualities in your containers, when they stack, there needs to be a lip around the edge of the container to contain our nutrient solution, secondly they need to be ridged enough to support the weight of the system.

The two containers I'm using are dog food containers (food safe plastic) of about 8 gallons capacity. We'll clean up the algae later.

To prep the bottom container. Take the lid of the bottom container and drill several holes into it using a 1 inch hole saw, then snap the lid on and drill a hole in the side of the container just below the lid line. that's that.

To prep the top container. Drill several holes into the bottom of the top container and two holes in line along the top edge of the container, Then snip them to make notches. Now cut a piece of window screen sufficient to cover the bottom of the container.

At this point wash the containers with a 10 percent bleach solution to remove dirt and algae.

Step 3: The Pump and Spray Bar.

We'll be building the spray bar in place to make sure it's right. stack the two containers. cut a piece of 1/2 inch pvc to sit in the notches cut in the top container, leave a couple of inches over hang for fitting attachment. cut a second piece and add an elbow, stick it in the hole in the side of the bottom bucket and now just cut a piece of pvc that will join those two pieces together. Add the end cap to the top piece and screw in the plug.

Now drill a bunch of 1/8 inch holes into the pipe across the top bucket to create the spray bar. Split the end going into the bottom bucket with a hacksaw about 1.5 inches.

The pump is attached to the spray bar with a piece of clear vinyl tubing, fortuitously the vinyl pipe slipped right into the pvc, the split lets me cinch it tight with a zip tie.

Step 4: Assembly and Planting

The bottom container is filled with nutrient solution, the pump and spray bar fitted into place through the hole in the side. Snap the top on and place the second container on top and fit the piece of window screening in to it and fill with washed perlite. The spray bar has enough play that it can be swung up and lifted into the notches cut in the top container.

Wash as much soil as possible from the roots of your plants before planting, otherwise follow general planting procedures, ie not to deep, not to shallow.

Place the unit in the sun and plug in.

To change nutrient solution (about every ten days) unscrew the plug and let the solution get pumped out, I catch it in a bucket to water containers. Mix up a new solution (Gen Hydro is very good) and slowly pour it in through the top of the perlite, optionally remove the top container and fill directly.

The unused lid from the upper container can be drilled and split to surround the plants, this limits contamination of the perlite by organic matter (leaves mostly) and algae growth.



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    20 Discussions


    6 years ago on Step 4

    Wow awesome simple design nice one


    Reply 9 years ago on Introduction

    Did you ever find a system made without PVC?  I am a Hydro farmer and use The Urban Farm ( which is for bigger plants like indeterminate tomatoes or watermelons but am still looking for the smaller type for lettuce and such. 


    11 years ago on Step 4

    this looks pretty awesome, I wonder if there are any others this simple. I would like to add to genius by suggesting a solar panel to run the pump.! I am unfamiliar with the requirements of these systems but does the pump have to run 24/7 or would a solar panel running it all day be enough?

    3 replies

    Reply 10 years ago on Step 4

    I imagine that the pump would have to run 24/7, otherwise the water would drain out of the perlite (leaving the roots dry) after only an hour or two.


    9 years ago on Step 2

    I would also like to know TheDeadMethod's question.


    10 years ago on Step 4

    The roots should be fine overnight. My understanding is that plants don't take in water at night, and without the heat of the sun drying out isn't an issue. I have a makeshift aeroponics system I built into a large 30 gallon garbage can with a 10 second spray every 15 minutes or so. I shut the system off every night when the sun goes down and the plants are doing just fine. I would imagine that perlite is going to hold more solution overnight than just roots hanging out in the air.


    10 years ago on Step 2

    Would stacking the containers and drilling through the bottom of the upper container through the top of the lower one (so the holes line up) eliminate the need for the lip? It seems you only need it because of the odd grooves in the bottom of the buckets.


    10 years ago on Step 4

    as long as the roots don't dry out, you are fine


    10 years ago on Introduction

    Wow. I'm building a greenhouse, and I was planning on using hydroponics. I think I'll use this.


    11 years ago on Introduction

    yes, this is very similar to my simple aquaponics system which I'll get up here shortly. It's been in use for well over a year with no issues.


    11 years ago on Introduction

    It sounds like you are flooding the medium all the time. Perlite has a tendency to get waterlogged. Have you had any overwatering problems?

    2 replies

    No, the perlite drains quickly, you end up with a film of continuously moving water with plenty of airspace within the media. The tomatoes grew great, no signs of problems (ie. catfacing, splitting, cracks)

    That's awesome. The most I heard of flooding was 15 minutes every 4 hours. Being outside in the heat must make the difference. Glad it works for you.


    11 years ago on Introduction

    I was just reading something that trebuchet03 posted about hydroponics (I originally found his post while searching the subject). I am just learning about this and he suggested I send you a email/post. I live in Clearwater Florida and would like to start some cherry tomatoes (I know it is late in the season) but via hyproponics instead of in the ground. Is it too late to start tomatoes and if so what else could I used to get into this form or gardening? Thanks for your time, hamrad


    11 years ago on Introduction

    I have wanted to try a hydroponic system for a while, but was a bit imtimidated by it. I think i'll try this