The end of the growing season has always been a bittersweet time for me. On one hand, we have all the food we just harvested but on the other, it also means we have to hang it all up until next year. Now we’re lucky here in Texas because we don’t have harsh winters. So I can grow a few frost tolerant crops like lettuce, but I still can’t grow things like tomatoes or beans. This is the time of year we have to get creative if we want to grow more food. One of the easiest ways to do this is to grow indoors, either with soil or more efficiently using hydroponics.
I’ve talked about hydroponics before in my 15 Ways To Grow Your Own Food post, and my brother just wrote a post about Aquaponics, which is like hydroponics with fish. My dad also teaches a whole hydroponics class. For those of you who may not know, hydroponics is a method for growing crops with nutrient-rich water instead of soil. Sometimes the roots hang directly down in the water and other times they sit inside a growth medium. A growth medium is an inert substance (meaning it won’t decompose) that supports the plant’s root system. The nutrient-rich water is then pumped through the growth medium. Hydroponics allows you to grow without soil or natural sunlight, so it’s perfect for the winter month and growing indoors.
There are a ton of different systems that you can build. Some are very elaborate and others are little more than a bucket. Today I’m going to show you how to build a quick and easy hydroponic system using recycled soda bottles.
Before I show you how to build the system let’s talk a little bit about how it works. This type of system is called a drip system. This means that the water drips down into the growth medium, then flows through the soda bottle and down into the next bottle. The water eventually drips down into the reservoir. Almost every hydroponic system has a reservoir – this is just a container that holds the majority of the water in the system. In my system, I just used a five-gallon bucket.
Inside the bucket, there is a water pump that pumps the water through a tube back up to the top of the system to drip back down again.
The soda bottles have clay beads at the bottom and coconut coir at the top. These are both growth mediums. The reason I’m using both is that the clay beads act as a filter so the coconut coir doesn’t clog the neck of the bottle and the water can flow continuously.
The plants are grown in the coconut coir in each bottle.
The whole system hangs on a simple wooden, frame but you could hang it on a hook on the wall or ceiling
Alright, so now that I’ve explained how it works let me tell you what you need to build it.
I have to confess first that this is not my original design. It’s from a website called 3dponics, but I’ve made a few modifications. They design hydroponics systems so that you can 3d print most of the parts. Don’t worry if you don’t have a 3d printer, I’ve come up with a way to build this system without one. I’ll mainly focus on doing it without a 3d printer in this post. So now let me get into the step by step.
First, let’s talk about the frame.
I made this frame out of some scrap wood I had in my backyard. The frame is simply a cross beam on top of two 6 ft. legs. You could also use an A-frame or hang it from the ceiling.
Next, you’ll need 4 two-liter soda bottles. You could use more if you have more vertical space or you could use less if you are making a window system. Here you’ll notice that different brands have differently shaped bottles.
Either shape will work, though, personally, I prefer to use the shorter more cylindrical bottles. I find that these have a wider opening when the bottoms are cut off. I went ahead and washed and peeled off the labels of my bottles.
Now we have to cut the bottoms off the bottles. These particular brand of bottles have a line near the bottom that creates a guild to cut along. If your bottles don’t have this line you cut about 2 inches of the bottom of the bottle.
Next, we have to punch some holes in the bottom of the bottles. All we have to do is use a hole punch to punch four holes evenly around the base of the bottle.
Now we can start stringing the bottles together. If you’re using the 3d printed drip nozzle all you have to do is lace some rope through the holes. If you’re building this system without the 3d printed parts you can either use these sprinkler heads that are available on Amazon, or you could also punch a few holes into the soda bottle tops themselves.
To attach them you’ll have to use what’s called a Jar Sling Knot. It’s relatively easy to tie and it’s really strong knot specifically designed for lifting bottles and jars from the rims.
You’ll need some rope that can support a good amount of weight. I’m using paracord here. You’ll need about 4 ft. for each bottle.
Start by taking the middle of the cord, fold it down then fold it down to form two loops.
Take the center two cords and lay the left one over the right one.
Now take the bottom center and take it up through the left loop, over into the second loop, and out through the right loop.
Next, take the top cord and flip it down.
Do it once more.
Now slide the knot over the neck of the bottle.
Repeat this process for all four of the bottles.
To join the bottles together just lace them through the holes and tie an overhand knot.
You’ll find that you end up with a loop after tying the knot you can just cut it in half.
To attach to a hook just lace the cord through two of the holes to create a loop and hang it on the hook.
Now you can attach your nozzles.
Now to prevent the bottles from clogging with coconut coir we need something cheesecloth or a screen. If you’re using the 3d printed parts there a is a strainer piece that goes in the bottom of the bottle.
I used cheesecloth here, however, one of the bottles still flooded with these nozzles and I had to take it off. So I would suggest that if you aren’t using the 3d printed parts using a stiffer screen. Either cut a piece out of an old strainer or use some window screen from the hardware store.
Now you can add your clay beads on the bottom and the coconut coir on top.
Now let’s talk about the reservoir. I actually changed mine out for a bigger one so that I can run two soda bottle towers next to each other. So if you’re wondering why this one is different from the bucket that’s why. However, a simple 5-gallon bucket will do.
As for the pump, I have a water pump that will pump up to thirteen feet high. However, it won’t quite reach that height here because it’s not deep enough and thus doesn’t have enough pressure. Luckily my bottle towers are only about 7 feet so this pump will work fine.
You can find this one on Amazon here. The tube I’m using is ⅝ in. O. D.
To spread the water out when it gets to the top I’ve drilled a few holes toward the end so it will drip down. I then ran it around the rim of the bottle and secured it with a zip tie.
Once you have your pump running add your nutrients.
Now you can plant your plants. You might be able to start seeds in this system but since it is constantly dripping I suggest you start them elsewhere and then plant them. Also be sure to offset them from the center so the water isn’t dripping directly on the seedling.
That’s it – now you know how to build an easy hydroponic drip system with some inexpensive materials.
So what are you going to grow this winter?