Figuring Out Fogponics
You’ve heard of aeroponics before, but what about fogponics? Sometimes called the next phase in aeroponics, fogponics is a hydroponic system that suspends plant roots in air and supplies them with nutrients via water droplets that are so small, they qualify as vapor. Here’s how it works.
If you’re into hydroponics, regardless of the system you use, you’re no stranger to water and nutrient management.
From DWC (deep water culture), to NFT (nutrient film technique), to aquaponic systems, the “hydro” in hydroponics gets top billing for a reason.
Soilless gardening relies on water as the primary vehicle used to deliver nutrients to hungry plant roots.
What may not be as obvious is the role oxygen plays. Leaves and stems help carry out photosynthesis, producing oxygen as a byproduct, but at the root level, plants need oxygen from the soil to help break down the food they need to survive.
Plants rely on the efficient delivery of water, nutrients and oxygen to grow to their full potential. And one system that delivers an ideal mix of all three of these essential items is fogponics.
Let’s take a look at a few different hydroponic options to help us understand what makes fogponics so special.
Media-based Hydroponic Systems
In a basic hydroponic set-up, media is a substitute for soil. There are lots of different types of hydroponic media, but they all tend to be chemically inert, heavy enough to anchor plant roots and porous enough to allow for good oxygen access and water/nutrient distribution.
There are some drawbacks to using media, though. Media can clog feed lines, entangle roots, harbor bacteria, algae or fungi, or lose porosity over time.
In some systems, switching from one type of media to another can be a problem, too.
In an immersion system, delicate roots remain in a liquid environment most if not all of the time, and definitely throughout a plant’s early development.
The anchoring media is replaced by a basket or other simple support structure that makes roots easy to see and easier to remove when or if plants are eventually transferred to soil or another growing environment.
When roots are suspended in water more than intermittently, they need special treatment in the form of supplemental oxygen.
The gaps and pores in conventional growing media make oxygen readily available to roots, and conventional hydroponic systems also include processes that remove and replace water and nutrients regularly, giving plants increased exposure to the air.
In submersion systems, oxygen is added through the use of an air stone, the same way oxygenated water is supplied to fish in an aquarium.
Because plants are in the water/nutrient mixture all of the time, pH fluctuations and temperature instabilities can happen suddenly and be devastating.
Aeroponics approaches things differently by bringing water/nutrients to plant roots suspended in air instead of providing oxygen to plant roots suspended in water. The basic idea is pretty simple. Plants are installed on a platform using a support collar.
The roots dangle below into a box structure containing a network of spray nozzles that deliver nutrients to them on a timed schedule. Excess nutrients are recycled and reused.
During the early development of aeroponics, some interesting things came to light. One of the most significant is that the increased access to oxygen in an aeroponic system enhances plant growth a lot.
Another is that the continuous delivery of nutrients and oxygen in lavish amounts is an efficient way to farm.
Plants don’t waste energy searching for food, and since there is no real competition for nutrients, and no incidental reduction in oxygen supply, plants can be grown in close proximity to one another, saving space, time and money. Sounds pretty good.
Fogponics: A Better Mousetrap
Fogponics is a form of aeroponics, sometimes called the next phase in aeroponic technology. Think of it as a refinement, but a significant one.
It uses the same basic concept as aeroponics—the practice of suspending plant roots in the air of a grow box and supplying water/nutrient droplets on a timed schedule.
In fogponics, though, the droplets are so tiny, they qualify as vapor. And in this case, smaller is better.
Plants absorb elements most efficiently in the range of about 1-25 micrometers (µm), and though foggers work somewhat differently depending on the manufacturer and model, a fogging system will supply vapor at between 5 and 30 µm.
While aeroponic systems supply nutrients to plant roots, foggers deliver vapor to stems and leaf nodes as well as roots, resulting in more efficient nutrient uptake and healthier plants overall.
Plants absorb droplets well, but because they absorb vapor better and faster, this can be good news for growers.
There’s less waste, good space conservation and less opportunity for error, especially during root feeding.
How can you make a mistake spritzing plant roots to feed them? Aeroponic systems rely on precisely spaced nozzles to spray the interior of a grow box evenly.
Sometimes there are voids, or plant roots can become so thick they create obstructions.
Clogged nozzles can also fail, killing plants that are locked out of water and nutrients. These types of problems may not be detected until it’s too late.
However, with fogging systems, wider and more comprehensive dispersion is much easier to accomplish, and growers are more likely to get to all the roots evenly and consistently.
This type of delivery system may also change the nature of the roots on some plants by encouraging smaller, hair-like growths that are even better at taking advantage of vapor-based feeding.
Disadvantages of a Fogponics Garden
There are some potential disadvantages to using a fogponic set-up, though. The fog vapor is difficult to confine, and may present a hazard to humans and pets in some circumstances. There may also be some problems with even dispersion of vapor when setting up a new system. Start-up costs can be high, and the equipment requires regular cleaning to keep from clogging, much like the nozzles in an aeroponic system.
Both aeroponics and fogponics are considered advanced methods of indoor gardening. They offer some real advantages over conventional hydroponic systems, but have one drawback: they both rely on the consistent delivery of water and nutrients through the use of timers and electricity.
During a power outage, whole crops can fail quickly. To avoid this type of catastrophe, implementing a secondary power strategy, like a generator, is a good idea.
Is fogponics the future of indoor gardening? Although aeroponics and fogponics are popular, conventional hydroponic systems still dominate the landscape. That may change in the future, though.
Written by Sara Elliott | Gardener, Writer