Updated: Mar 16, 2022
Soilless agriculture results in explosive growth rates and huge yields. Choosing the right hydroponic system will determine how much you’ll eventually harvest.
Photo Courtesy: Justin Cannabis/ High Times
Be Like Water
We’ve all heard of hydroponics and the great things that can be done with it. However, choosing which type of hydroponic method to use in your individual situation can be a dilemma. That said, I’ve taken it upon myself to inform and educate you, the information-hungry grower. I’ll cover the commonly used methods, outlining the pros and cons of each. Hopefully, these lessons will rub off on you, and you’ll make the proper decision to suit your individual requirements and situation.
Your hydroponic setup can be as complicated or as simple as you like—it’s up to you. You can incorporate pumps, aerators, valves and switches, or you can fill a bucket with nutrient solution and simply pour it over your soilless growing medium. The flexibility of hydroponics is one of the main reasons it’s so effective and popular.
Individual drippers deliver liquid plant food directly to rock-wool cubes/ High Times
Peat & Perlite (Soilless Mix)
This most basic of methods uses a common planting container filled with peat moss and fortified with perlite. This method is the ultimate no-brainer, requiring little or no maintenance for the entire life cycle of your plants—you simply feed them some nutrient solution once or twice a day and watch them explode into lovely green foliage.
Perlite is required to increase the moisture-holding capacity of your growing medium. It’s cheap, commonly available and wonderfully inert, so it won’t interact with your nutrient solution to rob your pride and joy of essential nutrients.
A rockwool cube with your rooted clone or seedling is slightly buried in the pre-moistened peat and perlite. Be sure not to cover the top of the cube, just its sides and bottom. Peat is very porous, so the roots have a very airy environment to grow through, and this moist, oxygen-rich environment is exactly what they need to gain a solid footing in the growing medium. Rapid and prolific rooting is the key to future foliage growth.
While this method is great, it has the drawback of having the growing medium retain harmful salts left over by the nutrient solution. You can combat this by replacing the nutrient solution with plain, pH-balanced water every four or five days. While this leaches out a large portion of the salts near the roots, it doesn’t get rid of them—they simply migrate down to the bottom of the growing medium.
Another drawback to this method pertains to pests—an infestation of critters is extremely difficult to get rid of with the peat-and-perlite growing medium. This is because the uneven surface of the medium is rife with tiny crevices and holes, perfect sites for any critters to hide and reproduce in. If you have an infestation, you’ll actually have to replace the top inch or two of the medium to get rid of the hidden pests that take refuge there from insecticide. These moist hiding places also conceal insect eggs that can transform into the next generation of pests.
With this method, feeding plants is as easy as watering any other houseplant you may have. You can do it when you come home from work, or before bed. It’s entirely up to you—just be sure to keep the growing medium moist but not extremely wet.
Ebb & Flood
This is the method that I used to cut my teeth in hydroponics. The ebb-and-flood method uses a growing medium of pea gravel, sand or something of the like. There’s a lot of flexibility here. The idea is to allow room for the roots to grow through the medium unimpeded. I’ve heard of people using everything from their childhood marble collection to aquarium gravel. Even rocks dug up from the driveway work (if you clean them well enough).
This method can be as complex or as simple as you want it to be. The most basic setup has a growing tray filled with the medium you’ve chosen, with a hose connected to the bottom of it. The other end of the hose is connected to the bottom of a bucket, which is used as a nutrient-solution reservoir. Fill the reservoir with the nutrient solution, and then lift the reservoir higher than the top of the growing-medium tray. The nutrient solution will flow from the reservoir into the tray, flooding the growing medium. Place the reservoir on the floor and the nutrient solution will flow from the tray back into the reservoir. Simple.
The major advantage of this method is that the roots are constantly moist and highly oxygenated. The solid, heavy growing medium—I recommend pea gravel—holds the roots better than do peat and perlite. There’s also ample room between the grains of the growing medium for the roots to grow almost entirely unimpeded. They’ll waste less energy trying to plow through the medium, making an extensive early root system. This lends itself to spectacular results later on.
One drawback to this method is that the tray has to be flooded three to four times daily, religiously. If you have a job, then your plants will suffer because you won’t be able to feed them sufficiently. This is a good reason to explore automating your ebb-and-flood setup. Use a pump to fill the tray, a float switch to signal when the tray is full and an electric valve that opens to allow the nutrient solution to flow back into the reservoir. An electric timer is also a must-have for this system.
You might be scratching your head trying to figure out how to implement this. Don’t worry: There’s a clever solution to this problem. Read on.
Plants grown hydroponically experience explosive growth rates/ High Times
If you want to use the ebb-and-flood method because of all of its perks, but you’re not home during the day and you’re no good with electrical things, here’s your solution: Use the same growing tray and medium as you would with the ebb-and-flood method, but don’t use a reservoir. With this system, the reservoir is replaced with an aquarium aerator. Hoses from the aerator are snaked along the bottom of the growing tray, and then the tray is filled with your growing medium.
The idea is to have the growing tray constantly filled with the nutrient solution (and growing medium). The aerator blows air through the perforated hoses on the bottom, keeping the nutrient solution from becoming stagnant. This process is known as aeration, and it’s what keeps the goldfish alive in your aquarium. The rising air bubbles circulate and provide a constant flow of the nutrient solution to the roots of your plants.
With a setup like this, you need only to check for critters every now and then and to replace the nutrient solution once or twice a week. It is the best solution for the working grower, providing absolutely amazing results with minimum complications. I’ve used this setup since figuring it out nine years ago, and I have absolutely no complaints. The pleasant hum of that aerator puts me to sleep at night.
Nutrient Film Technique
The nutrient film technique (NFT) is widely used in commercial operations because it is completely scalable, and it provides amazing results. You can expand your NFT system to cover acres of growing area if so inclined.
Basically, the nutrient solution constantly flows through a flat-bottomed tray or a wide, round pipe (PVC plumbing pipes work excellently for this). The solution is allowed to flow over the roots of the plant, delivering nutrients very efficiently. Because the plant roots are sitting in fast-flowing water, a large amount of oxygen is also delivered to them. Most NFT growers also aerate the nutrient solution in the reservoir to further increase its oxygen content.
No growing medium is used, so the roots expand at a phenomenal rate and amazing growth follows. Some common (legal) crops that are grown using this technique in commercial settings are tomatoes, cucumbers, peppers, zucchinis and even pumpkins.
While the advantage of this system is its phenomenal growth and infinite scalability, the foremost drawback is its complexity. To implement this technique, you need a high-flow pump, an aerator and a complicated network of piping or trays. The results are spectacular, but many feel the complexity and level of work involved aren’t worth it.
Another drawback to this method is the expense of setting it all up. The costs of a pump, aerator and assorted pipes add up quickly. It’s also very unforgiving with mistakes or oversights, which will cause headaches later on.
Roots expand quickly when misted with aerated nutrient solution/ High Times
This method is a spin-off of NFT, and the setup is almost the same. What changes, though, is the method of delivering the nutrient solution. Instead of having it flow over the roots, the solution is blown on the roots in a fine mist via a special nozzle, much like the fuel injector on your car. This method is still quasi-experimental, and it isn’t used very often. A major consideration is cost. Another factor is that no way (so far) has been found to keep the nozzles from getting clogged due to nutrient crystallization.
Aquaponics sounds like a no-brainer, but it’s actually the most involved way to grow hydroponically. It is a natural hydroponic method, using next to no processed chemicals. I’m mentioning it here only to be complete, though, as you wouldn’t actually use it in practice to grow your grass.
Basically, a crop is grown in a hydroponic solution (a growing medium is optional).
The nutrients for the solution are obtained by natural means, such as harvesting the effluent from a fish tank (an extremely rich source of the constituents used in regular, nonnatural hydroponics). The system has the benefit of being almost self-sustainable, but it’s extremely involved and labor-intensive to set up and maintain.
I highly doubt that marijuana has ever been or will be grown using this type of setup, but I felt I should mention it anyway.
While cost is always something to keep in mind, your skill level as a grower is also something that you must consider. First-time growers should use the peat-and-perlite method. This allows you to learn and to improve your grow skills using a very simple and forgiving hydroponic method. While the results won’t be as spectacular as you’d see when using some of the other methods, it’s still a very effective way to grow. You won’t be disappointed.
Be realistic about your requirements, space being the first thing to consider and therefore the deciding factor. If you want to squeeze your system into an area barely big enough for it, think about fixing a leak in a pipe with only a few inches between it and the wall. Not good.
Now for cost. The cheapest system I’ve outlined is the peat-and-perlite method, though I recommend the aerated-solution or ebb-and-flood method if you can swing it. The mild increase in cost is far outweighed by the results and the lack of headaches.
So those are the common hydroponic methods in a nutshell. I hope it will be useful to you. Best of luck in your growing endeavors!