Welcome to hydroponics 101 - where you'll learn how to grow hydroponics style!
We are going to take this opportunity to educate you on hydroponic growing, one of the most exciting and efficient ways to grow indoors.
If you're reading this guide, it's very likely this is your first encounter with this method, and you probably have no shortage of questions. Rest assured we are going to cover everything you need to know!
Whether you are already familiar with it, or a complete beginner - you will gain something valuable from this post, as we are going to take a deep dive into:
- What is hydroponics?
- What are the benefits of hydroponics?
- Who should & and who should not try hydroponics?
- The best hydro systems of 2021
- How to grow hydroponics plants
- And much, much more!
We've got a lot to cover, so without further ado, let's dive in!
What is hydroponics?
You are probably excited to learn how to grow hydroponics plants, but we've got a lot to cover before we get there.
The first lesson in hydroponics 101 starts with a definition.
It is defined as growing plants without the use of traditional soil or soilless mixes.
To be considered a hydroponic system, plants need to be either supported by an inert growing medium, or nothing at all. The only nutrients your plants get are what you feed them - directly at the root zone.
The ready availability of nutrients to the root zone is what leads to such impressive growth and yields with hydroponics.
What are the benefits of hydroponics?
While there is a steep learning curve with hydroponics compared to traditional growing, there is a reason so many growers swear by it.
First off, hydroponics is more efficient. You will use far less water growing this way.
In many cases, your water can be reused to further increase efficiency. This saves you money on water, while saving the planet! Win, win.
Faster Growth Rates
Another huge benefit of hydroponics is the accelerated growth rate you'll see.
You'll see 25% faster growth in a hydro system compared to traditional soil growing. This means less time to harvest, and more harvests per year!
On top of faster growth, you will also see an increase in yield. Hydroponic harvests can be up to 30% heavier than standard soil plants.
But, lets go back to our previous point of faster growth rates. This further increases yield.
If you can fit 1 or 2 more harvests in per year, you'll see even heavier yields over the course of a year!
But, it isn't all sunshine and rainbows. It wouldn't be fair to give you all the great reasons to try this grow method unless we also shared some of the drawbacks.
Disadvantages of hydroponics
There are all kinds of benefits to growing hydroponically. But, hydroponics isn't for everyone.
It's quite a bit more expensive than traditional soil growing, as systems can get pretty pricey. And, it's quite a bit tougher and more complicated than soil growing.
This Is A Tougher Grow Method For New Growers
It will take a while before you are comfortable operating a hydroponic system, and there is less room for error than with soil gardening.
If you have never grown before, we do not recommend starting with a hydro system.
You will need to pay very close attention to the pH and ppm of your hydroponic reservoir.
Since there is no soil to buffer out overfeeding, plants can be damaged. Use a high quality nutrient and pH doser to eliminate any human error!
Hydroponic Systems Are An Investment
The price of a hydroponic system is much higher than a standard soil garden.
But look at it this way - the increase in yields, decreased time to harvest, and savings on water make it an investment!
And, you can actually make a DIY hydro system on a pretty low budget. Now, let's move onto the next part of hydroponics 101 - the different types of grow media you can use.
Hydroponic grow media
As we mentioned earlier, a huge aspect of hydroponics is the absence of soil or soilless media.
Instead, you use something completely inert. The only real job of hydroponic grow media is to anchor the roots in place and provide support to your plant.
There are a number of inert growing media available for hydroponic growers. The most common are:
- Clay pebbles or growstones
- Coco coir
- Oasis cube
Rockwool is one of the most popular choices for hydroponics.
It provides exceptional aeration and water retention, and anchors the roots in place very well.
Clay pebbles and growstones are very similar, and are often times lumped into the same category.
These are a well renowned, 100% inert media. Coupled with the fact that these are pH neutral, growstones and clay pebbles are prized as one of the best options for hydroponics.
They are also reusable, and a sustainable option.
Coco is used in traditional gardening as well, but there are varieties specific for hydroponics.
Coco coir goes by a number of different names, and is 100% organically derived from coconuts.
It features a perfect balance of drainage and water retention. We have a complete guide to growing in coco if you're interested in learning more about this medium.
Oasis cubes, also referred to as hydroponic foam, are a popular way to start clones hydroponically.
They are probably the most simple way to grow hydroponically, and support the roots very well.
The aeration provided through the foam is unrivaled by any other hydroponic growing medium.
Not sure which hydro growing media is right for you? Check out our full hydro growing medium section for more info.
What are the different types of hydroponic systems?
Perhaps the most important aspect of hydroponics 101 is learning about the different systems.
Hydroponic systems can be broken down into two categories: active or passive.
A passive system is one where the water does not need to be transported to the plants, such as in a deep water culture system.
An active hydroponic system involves the use of a water pump actively move the water to the root zone.
Part of what makes hydroponics so complex is the variety of systems growers can implement.
A hydro system can be anything from a primitive wick system to the more advanced aeroponics systems.
There is no one set methodology that every grower must adhere to. This is what makes hydroponics so exciting.
The only common thread throughout is that hydroponics is consistently a soilless method of cultivating plants.
There are six known types of hydroponics, but we will only focus on the four most prominent systems in use today.
Also known as DWC, deep water culture is one of the most simple hydroponic systems available.
Your plant's roots are suspended in a reservoir filled with nutrient solution. This allows for a constant supply of nutrients to the roots.
DWC systems are great for those new to hydroponics, because there are few working parts. This makes it a low maintenance system.
The main drawback of DWC hydroponics is how easy it is to overfeed. Since the roots are submerged in the nutrient solution, there is no buffer to protect them.
It is very important to closely dose nutrients in any hydro system, but this one in particular.
This system is a little different than other hydroponic systems, as plants are fed through the top as opposed to directly at the roots.
In a hydroponic drip system, drip hoses will run from the water reservoir up to the top of the grow tray.
Here, drippers will slowly feed the plants. The main advantage of a drip system is the ability to control how much the plants are fed, down to each drop.
There are recirculating and non-recirculating systems. The recirculating system is one where excess nutrients drain back into the reservoir, and are fed to the plants again. This is a great way to increase efficiency in your system.
Aeroponics is the most advanced system in the hydroponics industry, and is a bit different than other types.
In an aeroponic system, the roots are suspended in air instead of a nutrient solution like the ebb and flow or DWC.
Inside the reservoir, sprayers will emit a fine mist of nutrients and water directly into the root zone of the plant.
The misting of the root zone is the most efficient way to feed plants. Aeroponics is the way of the future, and there are even aeroponic cloning machines now.
Part of what makes aeroponics so effective is the oxygenation of the root zone.
Unlike other hydro systems, the plants do not need the help of air pumps and stones.
Since they are suspended in air, they have access to all the oxygen they could need.
The ebb and flow system is similar to a DWC system in that the roots are suspended in a nutrient solution.
However, with an ebb and flow system, it happens periodically.
Also referred to as flood and drain, this system will work on set intervals and "flood" the roots with water and nutrients.
The roots will be submerged for a period of time. Then, the solution drains back into the reservoir.
Ebb and flow systems combine the availability of nutrients of DWC with the aeration of aeroponics.
What is the best hydroponic system?
The best hydroponics system depends on what your goals as a grower are.
We put a list of the top systems of 2021 together to make shopping easy. You can easily compare the best systems online, and make an informed decision.
You can read all about the best hydroponic systems here.
Breaking down hydroponic system components and accessories
Once you decide which system you want to use, you are well on your way to a hydro grow.
But, there are some components and accessories you still might need, depending on which system you choose.
Some of these are essential, whereas others are just going to make your grow easier and better.
Air pumps and air stones provide oxygen to plants
This is one of the most important components to any hydro system where the roots are submerged.
Since the roots of your plant will be under water, whether it be DWC or ebb and flow, you need to aerate the nutrient solution.
By using an air pump and air stone, you are able to provide oxygen to your plants.
How do air pumps and stones work?
The pump will sit outside the reservoir, with the stone inside.
A line will connect the two, and when powered on, the devices will deliver tiny air bubbles to the solution.
This creates dissolved oxygen, which increases your plants ability to feed, while also preventing it from drowning.
The importance of water filtration in hydro systems
Since we are feeding our plants water directly at the roots with no buffer, it is important to pay close attention to the quality of this water.
Filtering the water before it gets to the reservoir will ensure all harmful particles are removed, and you are in control of what you give your plants.
Reverse osmosis filters are the best way to filter for hydroponics, because they provide two steps of filtration.
The first filter removes large sediments that could harm plants. The second filter is a semi-permeable membrane for tiny particles.
Another common method of filtering water is with a dechlorinator and sediment filter.
This is especially important in locations where local water contains many chloramines.
Water chillers and heaters - because temperature matters too!
If you live in a particularly warm or cold climate, you will likely see temperature fluctuations in your water reservoir.
The root zone is a very sensitive part of the plant, and it requires very specific temperatures.
Try to keep the water in your hydroponic reservoir between 65-70 degrees Fahrenheit.
If temps raise too high, plants will be unable to hold onto dissolved oxygen. This can affect their ability to absorb nutrients.
If temperatures drop too low, the plants will get shocked, and stop growing.
If either of these situations is a possibility in your climate, you will need either a hydroponic water chiller or heater.
Here is some more information on why hydroponic water temperature matters.
pH & ppm meters
Since plant roots are constantly exposed to the nutrient solution in a hydroponic system, you need to make sure pH and ppm are within the optimal levels.
The optimal pH level for hydroponic water is between 5.5-6. If you want to learn more about measuring and adjusting pH, check out our full guide.
PPM meters indicate the concentration of nutrients in your water. This will indicate if you are under or overfeeding.
You will have different requirements for ppm depending on whether you are in veg or flower, and the nutrients you buy will provide a feeding schedule. To adjust your ppm, add more water or nutrients accordingly!
How do you build a hydroponic system?
For the final lesson in hydroponics 101, we want to teach you how to build your own system on a budget.
It's actually pretty simple. Here are the supplies you will need:
Keep in mind this will be a very primitive hydroponic system. An active hydroponic system will always be more effective but if you are looking for a cheap way to dip your toes in the water, this will work.
First, you will need to cut a hole in your lid to match the size of your net pot.
Then, you will put the net pot in the lid (with growing media) and measure where you want your water line to be in accordance with this.
The water line should reach the bottom of the grow medium and keep it moist, but not soaked.
Then, put your air stone in the bottom of the bucket and connect it to your air pump outside the bucket.
You are now ready to go! Anchor your plant in the net pot and let the root development begin.
You will need to regularly check pH and ppm of your nutrient solution, and adjust accordingly. Add fresh water every other week, or sooner.
How To Grow Hydroponics Plants - Best Practices, Tips, & More!
Now that you are aware of the premise of growing hydroponically, along with all the different types of systems and components you'll need to be successful in your endeavor, it's time for the main event in hydroponics 101 - how to actually grow hydroponics.
Of course, the basics are still the same in terms of taking a plant from seed to harvest - you want to propagate your seeds or start your clones, feed them nutrients, prune & train the plants, manipulate the lighting schedule to force them into flower, and then harvest.
However, there are plenty of intricacies you need to know about in order to grow your plants.
Here are some tips to help you get the best harvest possible out of your first hydroponic grow.
Using Hydroponic Plant Nutrients
We haven't spent a lot of time talking about the importance of nutrition for your hydroponic plants, only that the delivery of said nutrients will be more efficient.
But in reality, the nutrients you feed your hydroponically grown plants is critical to your success. If you dial in plant nutrition, you can see some of the most impressive growth and yields you've every achieved!
This is just due to the nature of hydroponics - direct exposure of nutrients to the plant's root zone.
When this hydroponic nutrient solution is aerated, it leads to insane nutrient uptake ability for your plant.
In our review of the top plant nutrients, you'll learn all about the best hydroponic nutrients you can use to feed your plants.
The reason you need to use specific hydro nutrients is because normal soil nutrients will clog hydroponic lines, leading to issues with delivery and uniformity. For this same reason, you should avoid thick, organic nutrients as well.
Cleaning & Maintaining Your Hydroponic System
Part of learning how to grow hydroponics is keeping your system clean and maintained. You'll need to use products periodically to prevent scaling and biofilm buildup.
These will lead to clogs and non-uniform distribution of nutrients. This leads to plant problems that you definitely don't want to deal with such as deficiency or toxicity of certain nutrients.
We recommend you check out our complete guide on how to clean salt build-up in your hydroponics system in the meantime, and understand how to keep things running smooth before you get started.
How Often To Change Out Hydroponic Reservoir With Fresh Water & Nutrients
Furthermore, you'll need to know when to replace the nutrient solution in your reservoir entirely.
While you can recirculate your nutrient solution for some time, eventualy, you'll need fresh, pH balanced water and properly dosed nutrients added.
In most cases, this is every 2-3 weeks. Of course, you'll want to watch the ppm's to decide whether you need to change it earlier or not.
Final thoughts on hydroponics 101
By now, you should have an understanding of the different hydroponic systems, and important considerations for growing in them.
This hydroponics 101 guide was just a 30,000 foot view of hydro growing in general, there is much more to it though. You have a good idea now of how to grow hydroponics plants, it's just a matter of taking action.
The key to hydroponics is precision with nutrient dosing, as you are in full control of how you feed your plants.
If you are new to growing, check out our definitive guide on indoor growing.
This will help you become a better grower in general, and teach you about taking a plant from seed to harvest. Then, you can apply that knowledge to hydroponic growing!