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The Different Types of Aeroponics Systems
How to Work with a Low Pressure Aeroponics System
Live in an apartment and share a garden? Or lack the space in your own backyard to grow the plants and veggies you’d like to? With aeroponics, you can grow more with less space and indoors too.
Even better news, the systems need far less watering because they’re closed-loop so you’re recycling unused nutrient-enriched water with delivery time controlled.
Let’s just say… If you’ve been doing any research into hydroponics, aeroponics will most certainly be on your list of get-to-know hydroponics systems.
That’s because of all six types, (Wick, Deep Water Culture, Nutrient Film Technique, Ebb and Flow or Flood and Drain systems and Drip Systems are the other five types of hydroponics) aeroponics, although the most technical of all types, will get the best results – every time! That’s guaranteed.
There’s a reason for that. It’s because there’s no growing medium used whatsoever.
This begs the question…
How do the plants grow using aeroponics?
And that’s the part you need to understand before you invest in an aeroponic system because there’s quite a few parts required for the technical set up that make it work.
If any component stops functioning as it should, your plants will die fast. That’s why you need to understand what’s happening under the hood – so to speak.
Understanding How an Aeroponic System Works
The setup of an aeroponic system needs quite a few components for healthy plant root growth. Up top, the only thing the plants need is light. Beneath the surface is where a lot is happening, starting in the reservoir.
You take care of the system, it in turn takes care of the plant roots and they, in turn, provide the nourishment the plant needs for healthy growth and tastier greens, tomatoes too even.
Here are the components that go into a properly functioning aeroponics system:
This is where all your water and the nutrient solution will be stored. It’s a closed-loop system, meaning whatever the plants don’t absorb, gets dropped back into the reservoir to be re-sprayed until the plant roots absorb the water solution.
The plants are never submerged in the water though. They’re suspended in air using net cups as grow chambers.
Secured to the base of the reservoir is a water pump that’s used to pump the water through the piping to the misting nozzles.
Repeat Cycle Timer
The repeat cycle timer is used to control the amount of water dispersed in the reservoir. If you research the recommended cycle times, you’ll find growers having success with a misting cycle of one minute on and five minutes off, and others having similar successes on misting for 15-seconds and then off for up to five minutes.
There are no hard and fast rules as to what frequency you set your misting intervals. The important part is that you do set it, because otherwise, the roots will be drenched.
Your best bet is to test every new plant when you start out because the best cycle is the one that lets the plant roots nearly dry out before hitting them with another burst of atomized water.
Different aeroponic systems will have a different number of misting nozzles used inside the chamber. These are an important part of the set up as the smaller the water droplet sprayed through the mister, the better the plant roots can absorb it.
A study by NASA research found that the best range is between 5 and 50 microns for the water droplets, which is the generally accepted standard for a high pressure aeroponics system. The finer the droplets the better the plants can absorb it.
Net Cups / Grow Chambers
Separating the plant roots from the plant tops is done using a lid with precisely cut holes to insert net cups that are used as grow chambers. These cups are inserted through the lid and sealed with (usually) a Styrofoam collar that provides both support for the stems and acts as a water barrier to keep the water contained in the reservoir.
All aeroponic systems have the same components and work the same way, but there are different types…
The Different Types of Aeroponics Systems
Low Pressure Aeroponics (LPA) Systems
An LPA system is the most common setup for home growers because of its cost-efficiency. They’re also the most widely available in a variety of places, not limited to hydroponic specialist suppliers.
It is possible to make your own LPA system using PVC for the piping, attaching misters to them and using a fountain or pond pump secured to a reservoir.
You don’t need a special pump for an LPA system. What you do need is enough pressure to create a mist in the reservoir.
The problem with finding the right pump for a DIY setup are that pond and fountain pumps don’t tend to have a PSI rating. Instead, it’s GPH (gallons per hour) and head height.
The head height is more important when choosing a good submersible pump for an LPA system because the higher the head height is, the more pressure is needed to pump the water up ‘til it reaches the misters.
You just need to be sure your reservoir is tall enough to accommodate the head height.
For best results, each spray should be angled upwards to spray above the roots and have each spray from the nozzles overlap slightly. You want the spray to create a fine mist and then the water to run from the top of the plant roots, then trickle down and drop back into the reservoir.
What you don’t want to do is angle the sprinklers to direct the water straight at the roots. That would drench them and likely drown them resulting in what some aeroponic growers term as soakaponics because the roots get soaked rather than misted.
Depending on the size of container you’re using, you could have just three sprinklers, or for larger setups, six or more sprinklers attached.
Several things factor into your water pump to get an ideal mist within the reservoir.
- The head height because the pressure needs to be forceful enough to travel up the piping to the misters.
- The more GPH the pump can push through the system to the head height required, the higher a pressure you’ll get.
- The number of misters used will affect its efficiency because with each mister, there’s going to be a slight drop in pressure.
Always remember that with a low pressure aeroponic system, you need to use the two ratings. GPH and head height.
And remember this part…
Whatever you think you need, go higher because you can always decrease the water pressure but you can never increase it without upgrading to a more powerful pump.
High Pressure Aeroponics Systems (HPA)
HPA systems are superb for commercial growers but a really costly setup for aeroponics hobbyists and home growers, so most likely unsuitable, unless you’re farming. This type of setup can really only be described as the commercial farming method of the future.
To get a peek into how growing is changing to have farms produce fresh vegetables in city centers, check out this video showing a super hi-tech aeroponics farming system in action…
In the 90’s, that would’ve been sci-fi. Today, it’s happening.
As you can see, using HPA systems is extremely technical and you can just imagine the cost it would be to set up a farm like this, which is why it’s only suited to commercial growers needing to grow more per harvest and get more yields per year.
A general HPA system pump will start with a range 60 to 90 PSI. The more powerful the pump, the finer the spray. For a professional grade setup, you’d be looking at a pump capable of delivering a steady flow of 100 PSI.
Regulating the frequency is where problems set in because these are running 24/7, so you can expect the pump to need replacing more frequently. And that’s just to water up to a half dozen plants. When you get into the hundreds, you’re then looking at a far higher cost for misters, pumps and tanks.
To extend the life of an HPA pump, a pressurized accumulator tank is used in a professional HPA system. Using an accumulator tank, there’s water and pressurized air used so that the pump doesn’t have to work as hard, and to maintain a steady PSI.
Due to the high cost of setting up an HPA system, there’s no use for them for home growers. There suited to urban farming as they are capable of producing far more yields per harvest and more harvests per year.
It’s the HPA system that focuses on getting minuscule water droplets of under 50 microns. Low pressure systems won’t produce as small of water droplets, but there will still be a fine mist created by the pump and the sprinkler heads.
Fogponics is a more recent advancement in aeroponics that really takes things to another level. Instead of your plant roots being suspended in the air and sprayed with a fine mist, a fogponics system doesn’t use a pump; it uses ultrasonic technology.
It’s a disc that’s submerged in the water and vibrates at extremely high frequencies that turns the water into a gas form getting water micron sizes down to just one micron and often less.
To really comprehend how small that is, one micron is equal to 1 millionth of a meter. In inches, it’s 0.00004.”
See how fogponics works in this short video:
For the purposes of this post, we’re going to be focusing on the setup most suited to home growers – the Low Pressure Aeroponics System because they’re the most affordable to set up and use, while getting a healthier grow using no growing medium.
You just need to know how to go about doing that.
How to Work with a Low Pressure Aeroponics System
Let’s talk Temperatures
The ideal temperature for any hydroponic reservoir is best maintained between 65oF and 80oF.
The most likely problem you’ll be faced with temperature is it dropping and that’s often related to the transfer of coldness from concrete floors such as your aeroponics system being setup in the garage or basement.
If you find the temperatures dropping below 65oF frequently, an aquarium heater with a thermostatic regulator should be used to maintain a higher temperature.
If the reservoir temperature is constantly too cold, it will slow down the plant growth. In addition, nutrient solutions added to the water in the reservoir will lose some of their effectiveness.
If on the other hand, you find your temperatures on the rise, which is more likely to happen in the summer months, you may want to use a reservoir chiller instead of the heater – if just turning the heater off doesn’t lower the temperature enough.
pH Level Consistency with Aeroponics Systems
The pH levels are super important in every hydroponic system. The reason being, the mist sprayed around the chamber cannot deliver everything a plant needs to grow. As the roots are suspended in air, there’s plenty of oxygen going to be available.
In addition, the cycling of the water misters will create a constant humid environment, getting close to 100% humidity constantly, which is one of the main reasons aeroponics is so effective at growing robust plants.
However, in addition to the oxygen, there’s essential minerals the plant is going to need that water alone cannot provide.
These include the essentials of:
The above are the main nutrients that need to be added to the water solution using a plant nutrient feed specifically designed to be used with aeroponic systems so that the roots can get all the nourishment they need for healthy growth.
In addition to added nutrition for the plants, there’s the issue of pH, which is a measurement of acidity.
This needs to be just right for each plant. Deionized/distilled water has a neutral pH of 7, but the ideal pH for aeroponic systems leans more on the acidic side of the pH spectrum, requiring a pH of 6.
This doesn’t need to be exact, so long as it stays above 5.0 and below 7.0, the roots will do okay.
A pH of 6 is ideal.
It’s also worth noting that a lot of plant watering advice emphasizes rainwater as being preferential. That it is. But, you also need to know that not all rainwater has the same pH, or nutrient value because of environmental factors.
Someone living rurally will have cleaner rainwater than someone living in Massachusetts, which has the highest rainwater acidity (pH of 4.1) of 15 states East of the Mississippi (go figure). On average, rainwater is slightly acidic with a pH of 5.6, but that will vary by region.
There are a few ways to test your pH levels with the most accurate being a digital pH meter. The cheapest method is just to use paper strip tests, but you will need to consistently monitor the pH of your water, so in the long run, it’s more cost effective to use a digital pH meter.
The other method is to use liquid pH tests. The digital meter is a one-off cost that you can buy once and use repeatedly.
As a LPA system is closed-loop, the water will recycle until the plant roots absorb it. Eventually, the reservoir will need topped up and when you do that, since regular water is more acidic than is preferred for aeroponics, you’ll need to use pH adjusters to maintain the consistency.
You can find a pH up and down solution on Amazon.
Using these, you can get your water and the liquid plant feed to the optimal pH of 6.0 and maintain it throughout the grow cycle of each of your plants.
Monitoring EC levels in Your Reservoir
EC stands for Electrical Conductivity and it can tell you a lot about how your plant is growing. Not just what’s in your reservoir, but how your plants are using what’s available.
Plants are smart creatures. They only absorb what they need. In warmer months, they may take in more water than they do any other nutrients. When the temperatures are cooler, they can take in more of the nutrient solution than they do the water.
Because of this, if your water temperatures aren’t maintained at a consistent level, you can find the pH levels alter, especially if your plants take in more water than the nutrients in the water.
When plants take in more nutrients than they do water, you could find leaf-burn becomes an issue. If on the other hand, more water is being absorbed than the nutrients, it’s going to slow down the plant’s growth rate.
Plants grow more healthily and faster when the EC is maintained at a consistent level. If during a cycle, you find the EC readings are lower than before, then the plant isn’t taking in enough nutrients or the solution you’re using isn’t strong enough. When the EC readings go higher, the nutrient solution is too strong and would need diluting.
Now, the tricky part is keeping the pH and EC consistent because the readings will alter every time you refill the reservoir due to the water starting out acidic before nutrients are added.
EC readings should be taken daily to make sure it stays the same and when they aren’t, nutrients should be added or the water diluted. Once a week or up to a fortnight, the reservoir should be cleaned and refilled with the right dilution of nutrient solution.
The reason being, if you don’t, different minerals such as copper and zinc can accumulate in the tank causing deficiencies.
Regular cleaning of the tank is a preventative measure to keep your grow healthy. During the week if there are changes, that’s when pH balancers (pH up and pH down solutions) can be used to tweak the nutrient solution being sprayed through the misters.
Just like the pH digital meters, you can use EC meters to measure the conductivity levels.
Now, because nutrients are delivering minerals into the water, it’s going to create salt and this is where you really need to maintain your system because if you don’t, the misters will get clogged causing the pump to work harder than it needs to.
Eventually, the entire system can be compromised because when there’s too high a salt level, it can clog your pipes and sprinklers and stop delivering any nutrients to your plants.
If that does happen, because the roots are suspended in air relying on oxygen, humidity and a constant supply of nutrient-enriched water, a failure can see plants die fast.
These aren’t like any other growing method where you can be lax with watering. Once the water stops being pumped effectively, the plants are compromised and often can be ruined. That’s why they need a lot of monitoring.
Not so much care, but more about keeping an eye on your readings to spot potential problems before they become a problem.
Different plants have different nutritional needs. If you know the EC range for the type of plant you’re growing, all you need to do is keep an eye on the readings to keep the conductivity within that range.
For a sample of common plants grown using aeroponics, there’s a handy table at GrowthTechnology.com showing a list of target EC ranges for a variety of plants.
When you’re growing with aeroponics, there’s not much you can do manually to treat plant problems because everything is entirely reliant on the system working properly.
Any issues of plant growth, fungi appearing on plant foliage or roots, or even leaf burn, will be because of an issue with your system.
The most common problems with aeroponics are:
Meet your worst nightmare. To put this in the simplest terms, don’t skimp on your water pump. Cheap pumps really are nasty with an aeroponic system because the life of your crops relies on this working.
Inside the reservoir tank is close to 100% humidity level – when the pump is working. The water pump is the reason for high humidity. When that stops working, humidity drops fast.
Combine the fast humidity drop along with the fact the pump won’t be able to spray any nutrients to the plant, the plant roots are then starved, which is why there’s a likelihood of your plants dying if the pump packs in.
The life of your plants relies on the water pump working. The instant it stops, there’s a serious problem.
This is an easy one to miss and it’s also an easy fix. You see, with all the nutrients in the water being sprayed through the nozzles, those minerals will accumulate salt. Eventually, the salt molecules can accumulate in the pipes, reaching the nozzles at which point they’ll block it.
A partial blockage will slow down the misting, whereas a full nozzle blockage will stop any mist being sprayed. For that reason, it’s best to regularly check your nozzles are working as they should be.
If they aren’t, the only solution you need is isopropyl – aka, rubbing alcohol. Just rub it over the nozzles and it’ll get to work breaking down the salt molecules and getting your nozzles unblocked fairly quickly.
Multiple Problems with bacteria and fungi – The One Solution Fix
If you’ve done any research into the pros and cons of aeroponics, you’ll no doubt be aware of bacteria and fungi being of a higher probability than any other growing method.
Well, that’s just not true. What is fact is that all the conditions bacteria and fungi need to grow and spread rapidly are present in the reservoir of an aeroponic system. Warm temperatures and a humid environment.
The truth is, there’s no more bacteria or fungi concerns with aeroponics other than one and that’s Pythium Root Rot. The only reason is because the Pythium disease has a spore that can swim, meaning once it’s present in your reservoir, it’s going to infect all the water, and be dispersed onto the plants with every spray of the jets.
There’s only one thing you can do here and that’s prevention because if you do get disease ridden water, your plants will have seen their day.
Hydrogen Peroxide is the solution to fixing all the concerns to do with bacteria and fungi and that’s because on contact, it’ll eradicate it.
It also brings a new problem to the table and that’s the fact it’s so strong it can kill your plants, so while you’re trying to protect your crops, you could actually risk killing them yourself.
You need to get the dilution part just right, which is even trickier than you’d imagine because the majority of hydrogen peroxide suppliers already dilute what they sell to you.
Food grade is the best you can use since most of your plants will be of the editable type. That’s 35% and there’s very few manufacturers certified to supply this high a grade of hydrogen peroxide.
The recommended amount of peroxide to use in your reservoir is 3% per gallon to last up to four days. If you’re working in liters, it’s just 3ml per 1 liter of water. Remember to use the 3% peroxide solution.
At this concentration, your plants will be protected against a variety of bacteria, pests and viruses.
Maintaining Your Aeroponic System
The reservoir is where you need to pay the most attention to for maintenance but don’t neglect your grow room.
Two words to remember to grow healthy crops with aeroponics are “sanitize and sterilize.”
1 – Sanitize
Everything around your grow room needs to be kept clean, dust free and, and free of anything that’s going encourage any bacteria growth. For cleaning, treat your grow room as your kitchen. If anything is spilled, clean it up.
For your plant foliage, you’ll want to keep those healthy by trimming off dead leaves, maintaining the temperatures and ensuring the right amount of light is reaching the plant foliage.
2 – Sterilize
The key area to keep sterile is your reservoir. You’ll also have the irrigation system (piping delivering the water) to keep sterile, ensuring there’s not too high a salt build-up that could block nozzles and decrease the system’s efficiency.
For this, hydrogen peroxide is the best solution you can use to keep your reservoir sterile while it’s operating. Between grows, that’s a different matter that’s addressed by a cleaning flush.
A cleaning flush will involve completely sterilizing the system using bleach or similar cleaning agents. A scrubbing brush is best used to make sure you’re getting into every crevice within the reservoir.
Once you’ve thoroughly cleaned what you can, then run the system with a diluted bleach solution so that the piping, and the jet nozzles get sterilized too.
Once your flush is done, you need to get rid of any chemicals you used to clean it by running the system with just water. Let the water get rid of any lingering chemicals then let oxygen do its part to dry everything before you put it to use again with your next grow.
Whilst the reservoir is the key area to keep sterile, any equipment you’re using such as pruners should also be sterilized before using on your plants.
Just one snip with a pair of dirty pruners could introduce plant pests or diseases, such as using the same pruner on outdoor plants then snipping one of your plants in your aeroponics system with those before sterilizing them.
Maintaining your aeroponic system is easy when you know why you’re taking each step you take. You’re keeping your grow room/area clean and tidy (sanitized) to prevent pests from being attracted to the area or airborne pathogens to be introduced that could affect your system and plants.
Sterilizing all the parts in the reservoir and the tools you use to tend to your plants is being proactive instead of reacting to plant diseases, common pests or any viruses.
With that out the way, time to assess…
The Pros and Cons of Aeroponics
After covering what aeroponics involves, including the various technical aspects of this method of growing, to wrap up, here’s a bite-size list of the advantages and the disadvantages of aeroponics to help you decide if it’s a good choice for you.
- Extremely fast plant growth.
- Only a small area is needed to get started if you use a vertical grow system.
- Less nutrients are used because it’s a closed-loop system. What your plants don’t use, drops back into the reservoir to be cycled through the system. Nutrients and water are in constant supply and your plants will only use what they need, when they need it – day or night as it runs 24/7.
- Ability to control the growing climate right down to knowing your plants are taking in the same amount of water as they are nutrients.
- Less worry about plant pests.
- Less water is needed and far less watering as the system will re-purpose water that isn’t absorbed by the roots of your plants.
- Totally reliant on the system.
- Growers need to be competent with numbers and accurate with measurements of plant feeds and any chemicals you’re using such as hydrogen peroxide.
- Regular checks needed for pH and EC levels.
- The constant moist environment of the chamber is inviting to bacterial pathogens and fungi, so while you’ll have less care to provide, you will have more inspecting to do to make sure your pH and EC levels are consistent and the reservoir is fungi and bacteria free.
There are less disadvantages than there are advantages, but the downside is that those disadvantages are really strong. It’s a high level of commitment so don’t be fooled by thinking there’s nearly double the upsides than there are downsides.
Depending how committed you are to trying aeroponics, it could set you back a few hundred dollars for a quality aeroponic system. If that doesn’t work out, you could have one expensive mistake on your hands.
That being said, it is a high-risk high-reward scenario because when the system is controlled to perfection, you will get a higher quality of crops at a faster production rate and much healthier plants than many other growing methods because of the 24/7 oxygen and nutrient supply to the plant roots providing full nourishment throughout the growing cycle.