Hydroponics, in its simplest definition, is a system for growing plants that doesn’t use soil. All plants require water, nutrients and a growing medium, of course. That said, growing plants hydroponically allows us to have more control of the plants’ nutritional needs and growing environment. In addition, hydroponics systems are easy to assemble, and adaptable for any growing space.
One major advantage of growing hydroponically is that plants grow faster and bigger than the same crop grown in soil. There are many types of hydroponics systems available on the market, and some can even be built at home using easily found items. Read on to learn about a few different hydro systems, as well as their advantages and drawbacks.
As I mentioned before, hydroponics systems don’t use soil. They use other growing mediums such as vermiculite, perlite, coconut coir, or rockwool. Most hydroponic growing mediums are great for holding moisture, but lack essential nutrients that your plants need to grow strong and healthy. It’s up to us to make these necessary nutrients available to our plants.
Hydroponics systems usually require electricity to run a timer, a water pump, an air pump and/or an air stone to oxygenate your water so your roots won’t drown. If your electricity goes out, or any of these components begin to fail, your plants will be directly affected. In contrast, some hydroponic setups—like wicking systems—don’t require any electricity at all.
One big downside of hydro can be the initial cost to get your system up and running. Buying an already-made system is a quick way to start, if expense isn’t an issue. Luckily, there are several ways to make your own hydroponics systems that won’t drain your wallet.
Since your plants won’t have soil to provide essential nutrients, you’ll have to provide them instead. Plants cannot live on water alone! Nutrient solutions can be bought at garden centers and hydroponics stores.
Although many nutrients are necessary, the important ones to know are: Nitrogen (N), Potassium (K), Phosphorus (P), Calcium (Ca), Magnesium (Mg), Sulphur (S), Zinc (Zn), Iron (Fe), Molydenum (Mo), Manganese (Mn), Boron (B), Copper (Cu) and Chlorine (Cl).
Passive Hydroponics: Wicking Systems
The first system I will explain is what is called a passive hydroponics system. A lot of gardeners I know don’t recognize wicking systems as an actual type of hydroponics. Unlike most types, wicking systems rely on water’s wicking capabilities quench your plants’ thirst.
Basic Wicking System
One fairly simple type of wicking system would be a trough (or a pot) that’s filled with a growing medium that holds water and nutrients well, such as vermiculite. A wick—cotton rope or even a piece of felt—runs down through your growing medium into a separate vessel that’s filled with water and nutrients.
Water wicks upwards into your growing medium, carrying with it the necessary nutrients your plant needs. This self-watering method makes wicking systems the simplest type of hydroponics out there. As long as you make sure to fill the vessel with water and nutrients, this wicking system should continue on without much maintenance needed.
Another type of wicking system that I really like, is the wicking bucket system. This system, unlike any of the others that I will mention, does require soil.
Building a DIY wicking bucket is a really inexpensive way to learn the benefits of passive hydroponics. It can be built using a clean food-grade bucket, a few sections of PVC piping, and about half a bucket full of small- to medium-sized rocks. You also need some type of cloth or burlap (I use old trampoline material), and about half a bucket of soil.
The trick to wicking buckets is making a water reservoir at the bucket’s bottom. This way, your plants can wick water on their own when they need a drink. This reservoir is created by the spaces in between the rocks at the bottom of the bucket. You can choose how big your reservoir is by how many rocks you add in. I usually fill up mine at least 6-8 inches. The bigger your reservoir, the longer you will be able to wait until you’ll need to refill it.
How to Build One
Place a PVC “fill pipe” vertically into the rocks so it sticks out above the top of the bucket. You’ll add more water through this pipe to water your plants. I suggest using a 2” diameter pipe to make filling easier.
Lay another piece of PVC with a few holes drilled into one side (making it look like a flute) on top of the rocks so it sticks out the side of your bucket. This is a drain pipe to pour out excess water. Make sure the drain pipe is flush with the top of the rocks, with drilled holes faced downward.
Then, place a layer of burlap (or some type of porous material) over top the rocks and the drain pipe. Cut or fold around the upright fill pipe. This layer will help to keep the rocks and the soil separate as time goes on.
Fill the rest of the bucket with soil and compost, being careful to leave the fill pipe uncovered. Transplant plants that already have a bit of a root system into wicking buckets, so their roots will be strong enough to wick up water. If you’re growing seeds in a wicking bucket, you’ll need to water them normally until they get bigger.
Pros and Cons
– Inexpensive and simple to build.
– Wicking systems are great for smaller plants that don’t use a lot of water or nutrients. Leafy greens, flowers and herbs are ideal, rather than anything that produces a fruit (like tomatoes).
– Good for teaching children or classrooms about plants’ water needs.
– Depending on the size of water reservoir, wicking systems (especially wicking buckets) will keep your plants happy for up to a week. Perfect for short vacations without having to worry about your plants!
– Basic wick systems aren’t recommended for larger plants. (Wicking buckets can handle a bit larger plants though.)
– If you don’t put your wick in the correct spot, your plants won’t thrive. In fact, they’re likely to die.
Unlike passive hydroponics, the next systems I’ll describe require electronic components. These are necessary for your system to run properly. If your power goes out or your system is accidentally unplugged… your plants will immediately be affected. I have met more than one hydroponics gardener who told me they’d lost (or almost lost) a crop because someone knocked out the power cord.
Depending how thrifty you are, these systems can be built at home for between $50 and $200. If you don’t have a hydroponics or a large garden center near you, finding specific growing mediums and some electronic components can be challenging. Searching your area for a hydroponics store is definitely worth the effort. Not only will you be supporting local business, but the folks who work at these stores usually have a wealth of free information. On the other hand, ordering supplies online is an excellent way to save some money.
Hydroponics systems are also a bit more challenging, since they’re more directly involved in the growing process. Like any type of gardening, know beforehand that you very well may not successfully grow ribbon-worthy plants your first time. After a few crops, you’ll get the hang of it and will know what to look for, and how to fix problems as they arise.
Deep Water Culture
A great hydroponics system for beginners is called a deep water culture system. The simple design and easy accessibility to building supplies makes them a great hydro system to start learning with!
In this system, plants are suspended above a large water reservoir in plastic nets. These nets are most commonly filled with small moisture-holding clay pebbles (called hydroton), and a chunk of rockwool for holding nutrients.
The rockwool also acts a base for your little plants to grow out of. You’ll have to check nutrient levels and adjust accordingly to your plant’s needs throughout their life cycle.
As the plants begin to grow upwards, their roots grow down further into the water reservoir. Unlike soil, there is no oxygen available in water so you will need to oxygenate it. This can be done by using an air stone that’s hooked up to an air pump outside the reservoir. Both can be found where aquariums are sold, like pet stores’ fish section. The air stone constantly creates tiny bubbles that help your plants’ roots get the air they need.
Two Easy Options:
Two inexpensive water reservoir options are Rubbermaid plastic tub,s or a food-grade 5-gallon bucket. Plastic tubs are great for growing a few plants at once, while the buckets are more suited for just one plant at a time.
A friend of mine likes to use individual 5-gallon buckets as the water reservoirs for each plant he grows using the DWC system. There’s a benefit in doing it this way. If you discover that your measurements are wrong or something else goes wrong, only the one plant will be affected. This is a great method for growing a “mother” plant that you plan to take clones from.
Pros and Cons
– Inexpensive and easy to build at home.
– Find most needed supplies where fish aquariums are sold.
– Low maintenance.
– Great hydro system to learn with and simple enough that children can understand, making it a great classroom project!
– Continuous nutrient level monitoring is required.
– Continuous non-interupted electricity is crucial.
– Air pump and air stone can malfunction after prolonged use.
– Does not work well with large plants or plants that have long grow periods.
Nutrient Film Technique
Another way to grow hydroponically is to use the nutrient film technique (NFT). This system uses similar electronic components as the DWC, with the addition of a water pump and a timer. A NFT system is a little more work to set up, but not overly complicated.
This hydro system consists of a long channel that holds plants in plastic nets. Nutrient-rich water is run down the channel, making contact with each plant’s roots. The water is dropped back down into a water reservoir, and then recirculated back through the system.
An inexpensive way to make the long NFT channels is to use wide PVC piping. These channels should have a slight downward slope. This slope, as well as having the right flow rate, helps the nutrient-rich water to easily come in contact with your plant’s roots. It usually takes a bit of time and observation to figure out the best slope and flow rate for your system.
The plants in an NFT system are usually grown in a rockwool cube, surrounded by hydroton in plastic nets. The roots grow down through the nets and are fed through the water “film” that’s continuously poured through the sloped channels.
After running through the channel, water is dumped back into the water reservoir. The water is oxygenated (with an air stone and air pump) and then recirculated back through the system (with a water pump on a timer.)
Pros and Cons
– Fairly inexpensive and relatively easy to build at home.
– Great for plants like strawberries and herbs.
– Depending on the length of your channel, up to a dozen plants can be grown in a single channel.
– Plants grown in NFT systems are usually smaller, so less growing medium is needed (compared to DWC systems).
– Plants can be harvested and replaced easily, as needed.
– Plants sharing water can also share disease or miscalculations from grower. As such, a single mistake will affect every plant in the system.
– More monitoring and observation is necessary to ensure proper flow and nutrient content of water.
– Multiple pumps and electronic components make this system heavily reliant on uninterrupted electricity. Power outages and knocked-out plugs will quickly affect your plants.
– Since plastic nets are usually smaller, roots can clog channels and quickly outgrow their personally allotted spaces.
Other Hydro Systems
There are many other hydroponic systems as well, though most of them are more expensive to build and require even more attention and monitoring. I’ll briefly mention these other hydro systems, so you can continue your own research if you’re interested in growing with them.
Ebb and Flow systems
These systems consist of trays filled with a growing medium. Water fills up in the tray and then drains out on a timer. As a result, the plants’ roots aren’t continuously exposed to water, which can allow the roots to dry out if not timed properly.
Drip systems are commonly used in commercial greenhouses very efficiently. In contrast, using a drip system for a small operation may not be worth your time. This system drips water down onto plants that are hung in plastic nets with growing medium. As a result, after plants are finished with the water, it’s sent down a channel into a reservoir and recirculated back through the system again.
Growing plants aeroponically can yield slightly higher harvests, if done correctly. Suspend plants, and mist nutrient-rich water onto them through a nozzle. Some growers put this nozzle on a timer, some don’t. Aeroponic systems aren’t as high-tech as you may think: they’re still relatively simple to build at home.
This system is a symbiotic relationship between plants grown hydroponically and aquaculture (animals that live in water.) I’ve seen several successful aquaponic setups, all of which used a system similar to the DWC. The most commonly seen aquaculture that I’ve witnessed is with Tilapia fish, though any aquatic animal can be used. Other commonly used animals are snails, crawfish, and catfish. One drawback I’ve noticed is trying to keep the fish alive over winter.
Hydroponics Systems are for Everyone
As explained in this article, most anyone can build some type of hydroponics system at home. With a little time and patience, you can master the skills needed to grow delicious hydroponically grown produce.
Growing with hydro is fun and lets us all “be the scientist” as we monitor nutrient levels and other important aspects. This information can be very insightful and doesn’t have to only be relative to hydroponics. These insights will help you understand your plants better—even in our good old-fashioned soil-grown gardens.