LPA
Low pressure systems rely on a simple pump, like those found in ponds or backyard fountains. This is a low-investment design since the pumps for Low Pressure Aeroponics are much more accessible than fine misters used in higher pressure designs. Therefore, most DIY designs will end up essentially being ‘soakaponic’ designs, a word used to describe the “soaked” quality that comes from the light spray, rather than mist.
Low pressure aeroponics systems are incredibly popular due to their low level of initial investment and set-up. All that’s required are simple, low-pressure sprinklers, rather than the expensive equipment that comes with true atomization.
‘Standard’ fountain or pond pumps are perfectly suited to low pressure aquaponics. As each sprinkler head is added, pressure in the system, or PSI, will drop. Typically, fountain and pond pumps don’t advertise their PSI rating. However, the more GPH (gallons per hour) it’s capable of pumping, the more pressure the pump will have. The higher the head height, the more pressure there will be, but this will need to be taken into consideration when designing your reservoir.
Ideally, your sprinkler heads will overlap in order to fully cover the entire root zone, even as the plants grow, and the roots grow along with them. If the roots of a particular plant are especially thick, it may be hard for spray from a sprinkler head to penetrate within the roots. In this design, it may be ideal to install the sprinklers above the roots, so that gravity gradually pulls water down through the root zone, rather than dripping off the bottom immediately. Too much moisture can cause root rot. Each additional sprinkler head will reduce the pressure, so it’s essential to use the minimum number of sprayers possible while still ensuring adequate moisture.
HPA
True mist, which involves incredibly fine water droplets, means that more moisture is suspended within the air, and nutrients are more effectively delivered to the root zones. However, a true mist requires higher water pressure than an ordinary fountain pump can provide. High pressure aeroponics relies on a pressurized water tank that can hold up to 90 psi, alongside high-quality sprinkler heads/misters. This fine mist provides more oxygen than a low-pressure system would, but the equipment and installation may be more expensive.
Typically, a high-pressure aquaponics system requires the following:
- A pressurized reservoir tank
- A valve in order to open and close the lines attached to the mister
- A cycle timer to open and close the above valve
- Fine spray mist heads
- A small air compressor to pressurize the reservoir tank
- Enclosed growing chamber for the roots
- A collection method for runoff
A high-pressure growing chamber will have the same fundamental design as their low-pressure counterparts. The water and nutritional solution delivery systems, on the other hand, will need to be changed. A water pump would need to be turned on and off from hundreds to thousands a time a day in order to maintain the proper pressure. The pump is removed in high-pressure systems, and the reservoir is pressurized instead. A twin chamber tank is commonly used to do this. On one side, nutrient-rich water is kept, while compressed air is kept on the other. The air pressure is increased to the desired level, which is normally between 60 and 90 psi. The air then presses on the dividing diaphragm until the pressure on the reservoir side equalizes.
Pipes or tubing runs from the reservoir to the sprinkler heads within the growing chamber. The valve is used to open and close water flow, controlled by a cycle timer. This on and off cycle is continuously used throughout the day, ensuring that the roots are never too dry.
Ultrasonic Fogger Aeroponics
Fogponics uses an ultrasonic fogger in order to atomize the water. Ultrasonic foggers use high frequency vibrations to break up water into its individual atoms, which we know and see as fog. These miniscule droplets of water are incredibly effective when it comes to plant absorption.
There are some things to consider if using an ultrasonic fogger. The fog or mist created by the fogger may collect along the bottom of the container, making it hard to ensure that roots are properly moist at all times. Plates or other equipment may clog due to mineral build up. This may be solved by wiping down equipment with white vinegar.
