How a Self-Watering Hydroponic System Works
Self-contained self-watering hydroponic systems like those made by Mufga and iDOO are marvels of gardening technology. All you do is plant the seed, fill the reservoir, and add plant food. The device does the rest for you. Just amazing.
But how does the system work? How can these planters grow such healthy plants and do it so quickly? The answer is, some very thoughtful engineering.
What is Hydroponics?
Hydroponics is growing plants with their roots submerged in or bathed in nutrient-rich water instead of soil. You use no soil in a hydroponic growing system.
Hydroponics can be done indoors or outdoors. The water can be stagnant or flowing, or a combination of both. You can grow one plant in a jug of water or hundreds in long PVC tubes.
- INDOOR GARDENING MADE EASY: Enjoy abundant harvests year round with the AeroGarden Harvest Elite 360, an indoor hydroponic gardening system that grows your favorite vegetables, herbs, or flowers in water without the mess of soil
- ROOM FOR 6 PLANTS: This round, stainless steel countertop garden features a spacious grow deck and water bowl so you can grow 6 different live plants at once, all up to 12 inches tall
- HIGH-PERFORMANCE GROW LIGHT: The full spectrum 20W LED grow light with an automatic on/off timer mimics natural sunlight to help plants germinate up to 5x faster than in soil
- FEATURES AND BENEFITS: Our indoor garden’s touch-sensitive illuminated digital display control panel reminds you when to add water and plant food while vacation mode keeps your plants healthy while you're out of town
- WHAT'S INCLUDED: The AeroGarden Harvest Elite 360 comes with a 20W LED grow light system, power adapter, one 3 oz. bottle of liquid plant food, and the Gourmet Herb Seed Pod Kit featuring Genovese Basil, Curly Parsley, Dill, Thyme, Thai Basil, and Mint
What is a Hydroponic Growing System?
A hydroponic growing system is a “garden in a box” for growing plants indoors.
The hydroponic growing system mimics the outdoor environment for the plant, but better. A timed LED grow light replaces the sun. The self-watering system simulates rain. A grow plug (a small cone usually made of peat moss) and nutrients added to the water substitute for soil as the anchor for the roots and food for the plant.
A countertop system can grow 6, 9, or even 12 plants. Larger systems the size of an end-table can grow 24 or more plants. That sounds unimpressive until you know that a hydroponic growing system can grow a plant healthier, bigger, and quicker than one grown outdoors, and your indoor garden produces food year-round.
Convenience is the main attraction of hydroponic growing systems; you need only supply water and electricity and nutrients. These systems are so well-thought-out. There’s no gimmick; hydroponic growing systems work.
But how, exactly, does a hydroponic growing system work?
- NEXT-LEVEL GROW SYSTEM: Using Aerospring’s patented aeroponic technology, this all-in-one grow system doesn’t require any additional components to grow like a pro. The root zone is contained in the modular vertical pole, and allows the plant’s roots to grow to their greatest potential. In addition to the Aerospring aeroponic system, the grow kit comes with everything you would expect including: 180W grow light, quiet exhaust fan, carbon-filter, metal frame, D600 grow tent.
- HIGH QUALITY 180W LED GROW LIGHT: The all new, Aerospring Hexglow custom 180W custom LED light panel, full-spectrum, professional grow lights, highly efficient at 2.7 (umol/J), light intensity at 1272 PPFD (μmol/s) at 15in, CRI >90, CCT = 4000k, estimated lifespan 50,000 hours. Suitable spectrum for all stages of plant growth. 0-100% light dimmer included. Adjustable light height can be raised as the plant canopy grows.
- DESIGNED BY GARDENERS, FOR GARDENERS: We designed the Aerospring system to be the most usable hydroponic system. Easy access to the water reservoir for water management. The 20 gallon reservoir requires less frequent refilling. Easily detachable internal hose for draining/changing water. The vertical pole is easy to disassemble for cleaning and reassembly, and dishwasher safe. The wheelbase allows for easy movement and rotation for trimming leaves.
- TEMPERATURE CONTROLLED: 4" carbon air filter with Australia virgin charcoal, changeable pre-filter. Quiet 4" inline duct fan with 0-100% variable speed controller, cutting edge brushless EC Motor and dual jet type blades, delivers 160 CFM airflow rate using just 18 watts at maximum speed for discreet and high performance growing.
- GROW TENT FOR DISCREET GROWING: The fully sealable grow tent made with Oxford D600 tent material, with highly reflective white interior panels, increases plant growth while eliminating 100% of light seepage. Two colors available, gray and black, to fit with any interior.
- IN THE BOX: The Aerospring Grower’s Edition Indoor Hydroponic System includes the Aerospring patented vertical pole with 9 plant capacity, 20gal bucket & lid, Aerospring Hexglow custom 180W LED light panel and driver, Quiet 4" inline duct fan, 4" carbon air filter, Powder-coated metal hexagonal frame with wheelbase, Oxford D600 tent, Sicce Syncra Silent 1.5, Smart WiFi Power Strip, SCROG Net, 1L Aerospring Hexgrow (A&B) nutrients, LCD Hygrometer, 9 Grodan Rockwool cubes, 9 Grow cups. Warranty: 12 month manufacturer's warranty on all parts; 24 months manufacturer’s warranty on Hexglow LED light panel; 3+2 year manufacturer’s warranty on Sicce Syncra Silent 1.5 pump. Seedlings not included.
Self-Contained, Self-Watering
The self-contained self-watering hydroponic systems on the market share a common design. The simplest device needs five components to function.
- Water reservoir
- Grow light
- Water pump with circulation system
- Tray with mounts for plants
- Timer (controller)
Manufacturers have bundled these components into a compact, easy-to-use indoor garden. Manufacturers added conveniences like WiFi and Bluetooth to some models. You can monitor and control your garden with an app on your phone.
Components
How does the self-contained garden on your kitchen counter work? To understand the process, you need to know the components that make up your indoor garden.
Water Reservoir
The bulk of the size of the device is the water reservoir, a tub holding water. The water pump and water level sensor are mounted in the reservoir. The reservoir lid is a tray. Roots from plants suspended from the tray float in the water in the reservoir.
The plants drink the water through their roots, so you’ll need to top off the reservoir periodically. A larger reservoir allows you to go longer without adding water. The number and type of plants you grow also affect the time between reservoir refills.
The water reservoir detaches from the frame to make cleaning easier. The power cord to the pump disconnects easily. The pump and water sensor can be removed with little effort for a very deep cleaning or replacement.
LED Grow Light
A LED grow light differs from the lights you use to light your room, even if that light is also a LED light. The LED grow light provides plants with the wavelengths of light they need to grow. The LED grow light combines red and blue lights with white light.
The LED light is very bright, as it must replace enough sunlight to nourish the plants.
The LED light is on a timer that keeps the light on for about 15 or 16 hours per day.
Frame
The frame of your indoor garden provides a base for the water reservoir, a tower for the light assembly, and a protected housing for the computer. The frame presents a control panel on the front or top. Electrical power comes into the device through the base.
Reservoir
The frame provides a fitted base for the water reservoir. The tub rests on the base so the frame does not actually hold any water.
The water reservoir detaches from the frame to make cleaning easier. Simply detach the power cable for the water pump and lift the tub from the base.
Depending on the manufacturer, you may be able to run the tub through the dishwasher (after removing the pump and water sensor).
Light Tower
The frame provides an adjustable tower for the overhead light assembly. The tower allows you to set the height of the light assembly very low when starting a garden and gradually raise it as the plants grow.
The tower extends to twelve or fourteen inches for the average-sized countertop hydroponic system.
Control Panel & Computer
The frame provides a control panel for you to enter settings to be stored in the computer. The frame protects the computer in a housing below the reservoir.
You won’t see the computer.
Grow Tray
The grow tray rests atop the water reservoir like a lid. The grow tray has holes where you’ll insert pods and another hole for adding water to the reservoir. The pods dangle down into the water reservoir so the grow medium is partially submerged.
The grow tray takes in water pushed by the pump submerged in the water. The water flows through tubes to each pod, where the water spills out over the grow medium.
The tray might be dishwasher-safe.
For some hydroponic grow systems, the grow tray can be swapped out with a starter tray. The starter tray provides many small holes for starting seedlings you can transplant outdoors or into soil-based containers. The starter tray is typically an optional accessory.
Pods
Pods are plastic wire-frames in the shape of a cone about 4 inches long. A pod holds the grow medium which holds the seed. The grow medium is (typically) sorghum peat moss formed into a cone shape. The peat moss replaces the soil.
You may find pods for sale with grow medium and seeds already in them. This is a convenience if you just want to drop the pod in and be done. The company should guarantee germination within a set time frame (likely about 21 days).
- For use in all AeroGarden models
- Our grow pods are made from coir and provide soil-free, no-mess, indoor growing all year round
- Includes all the supplies you'll need to grow your own favorite plants - 50 grow sponges, grow baskets, pod labels, six 3 oz. bottles of patented specially formulated liquid nutrients, and a growing guide with step-by-step instructions; seeds not included
- Grow your plants to maturity and harvest right from your AeroGarden or easily transplant seedlings and plants outdoors when temperatures are ideal
- Our Grow Anything Seed Pod Kit allows you to plant and grow your own choice of favorite seeds in your AeroGarden
Alternatively, you can buy the parts and insert your own seeds. You drop a seed down the hole at the top of the grow medium cone, drop the grow medium in the pod, and drop the pod into a hole in the tray. To prevent algae growth, you paste a sticker over the top of the pod. The sticker blocks the light from hitting the water but allows the plant to grow up through the center.
The pod comes with a clear plastic dome. Place this dome over the hole in the tray to retain some humidity inside the pod. It’s like a teeny-tiny greenhouse built for just one plant.
Once the seedling grows large enough to touch the transparent dome, remove the dome.
Computer
The computer drives the control panel and manages the timers for the pump, light, and feeder notification. If the device includes Bluetooth or other conveniences, the computer runs those as well.
The computer turns on the LED light for about 15 to 16 hours per day. The length of time the light stays on is determined by the manufacturer, but some units allow you to adjust how long the light stays on.
The computer runs the pump for a short time every 30 to 60 minutes, again depending on the manufacturer. The timer on the pump is not something you can adjust in most cases.
The computer is embedded in the base of the frame. It is not user-serviceable.
Control Panel
The control panel is your interface with the hydroponics system. The device communicates to you and you issue commands back through the control panel.
The minimum features of a control panel on a Hydroponic Growing System cover four basic functions.
- Initialize a "growing season"
- Set the daily "turn on" time for the light
- Turn the light on or off apart from the timer
- Reset feeding timer
The control panel includes an indicator (at minimum, a light) that communicates to you when the water reservoir is running low and needs attention.
The control panel may include more functions than the basic four. If the device includes a fan, the control panel may include a power and speed control. Some devices allow you to customize light colors emitted by the LED light to fit the stages of plant life.
Some units have a LCD screen for more advanced control over the growing process.
Water Level Sensor
You want your garden to always maintain a minimum water level in the reservoir. Your plant suffers if the water remains below the minimum level for an extended period of time. For this reason, the garden system should include a water level sensor.
The water level sensor is inside an enclosed tower in the water reservoir. The sensor is not directly connected to the computer. AeroGarden devices used a rod with a bobber (floater) at the top and at the bottom a material the sensor in the frame can detect. The sensor in the frame detected the proximity of the rod through the floor of the water reservoir and top of the base of the frame.
As the water level goes down, the bobber drops, which increases the reading on the sensor in the frame below the rod. When the sensor in the frame detects the rod getting close, the computer activates the low-water notification on the control panel.
When you pour water in the reservoir, the bobber rises, which reduces the power the rod has on the sensor in the frame. Eventually the distance between the rod and sensor grows so much the computer turns off the low-water-level indicator light.
You want a device with an automated water sensor that catches your attention if the water level drops too low. If your device offers only a window into the water level and you forget to add water to the reservoir, your plants can die.
Water Pump
A water pump inside the reservoir pushes water through the tray to the pods. The computer activates the pump at regular intervals. The water pours down on the grow medium inside each pod to wet the seeds and roots.
A filter protects the pump from ingesting the roots and debris that finds its way into the water reservoir.
The pump is replaceable.
A lever on the pump assembly allows you to adjust the volume of water the pump pushes to the tray.
How the Self-Watering Garden Works
The self-watering hydroponic system is an ingenious self-contained garden. In a compact package you can grow a variety of plants with very little effort. It’s amazing. But how exactly does this thing work?
Your device has four systems that work independently but when put together make your hydroponic system grow a bountiful garden.
Lighting System
The lighting system is a rectangle or circular LED assembly that hovers above the grow tray. The assembly height is user-adjustable so the light can be raised as the plant grows taller.
The lighting system for a typical countertop hydroponic system is 20 to 30 watts. That is enough power for the LED assembly to produce a very bright light. The LED assembly includes some red and blue LEDs mixed in with the white LEDs. The light level and mixture of colors simulates sun light.
The computer turns on the light at the same time every day. The computer leaves the light on for approximately 15 hours.
The light cycle system operates independently of all the other processes inside the garden. This is important to understand. It’s just a timer turning a light on and off once a day.
Water Cycle System
The water cycle system is a powered water pump and a series of tubes through which water flows.
The computer runs the pump for five minutes every thirty minutes. (This time interval varies by manufacturer.) The pump pulls water from the tub and pushes that water through tubes embedded in the tray. The water exits the tubes at the hole for each pod and pours down onto the grow plug inside the pod. The water thoroughly soaks the plug, which also soaks the seed or plant itself, before the water falls back into the tub.
The water pump operates independent of the other systems in the garden. Like the light system, the water cycle system is just a power switch on a timer.
Water Level System
The water level sensor is a nice piece of engineering. It solves the problem of determining the water level in the tub without actually wiring a powered sensor in the tub itself.
The tub has a column in it. Remove the column and inside you’ll find a rod-shaped bobber. (Pay attention to which end goes up so you reassemble it correctly.)
The bobber floats, so it rises and drops with the water level. The frame has a sensor that detects when the bottom of the bobber gets close. The bobber gets closer to the sensor as the water level drops. When the bobber drops below the minimum water level, the computer activates a light or sends a message to inform you of the low water level.
The water sensor system works independently of the other systems, although some manufacturers might program the computer to disable the pump if the water level is too low.
Feeding Notification
The garden notifies you when it’s time to feed your plants. Feeding notification could be implemented one of two ways.
One way to implement a feeding notification system is through a simple timer that reminds you to add water at set intervals, like two weeks. For the simple timer, you press a button to clear the notification and reset the timer.
A more sophisticated feeding notification system uses a sensor to read the percentage of nutrients dissolved in the water. With a sensor, the computer alerts you when the percentage of nutrients falls below a set threshold.
The feeding notification system works independent of other systems in the garden. That means if you fail to respond to the notification, the other garden systems will just keep going.
The Whole System
The three timers (light, pump, and nutrients) and the water level indicator may function independently, but when combined they form a system. This system pampers your plants in ways living outdoors in soil cannot.
And you get a bountiful harvest for it.
Key Takeaways
The explanation of how the various components work together and systems work independently hopefully took the mystery out of the internal workings of these indoor gardens.
Better still, knowing how the system works aids you in diagnosing and resolving problems and maybe even improving on the system. You’ll have a better foundation for determining whether various accessories will improve the performance of your hydroponic system or increase the yield of your garden.
You’ll be hard-pressed to find a more efficient means of growing certain foods than a Hydroponic Growing System. Use what you’ve learned here to select the best gardening appliance for yourself.
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