AeroGuide

Aeroponics is still a relatively new cultivating method for plants, which means that information on this topic is pretty rare to find so there is still room to experiment and learn. The purpose of this guide is to share our experience and make it easier for you to getting started with this fascinating form of growing plants.

What is aeroponics?

Aeroculture (also called aeroponics) is known as the most skillful technique of cultivating plants, because there is a thin line between success and failure. In this growing method environmental changes have immediate impact on the development of the plant, positive as well as negative. In aeroponic systems the free hanging roots are getting sprayed with nutrient solution in specific timed intervals. Hereby high pressure systems are supreme over low pressure systems due to finer water atomization. Besides optimal humidity in between spray intervals the roots highly profit from nearly unlimited availability of Oxigen. This allows the plants to maximize nutritional intake and grow much more efficient. With the roots hanging in free air there is no need for a medium therefore disposal of soil, rockwool or coco is not necessary. This is why even NASA prioritizes aeroponics and published these results in comparison to hydroponics or soil:

up to -98% water consumption
up to -60% fertilizer consumption
up to -100% pesticides

in return for up to 75% more yield
up to 80% more dried biomass per m²

[Source: NASA: gov/pdf/164449main_spinoff_06.pdf; Date: 04.09.2019]

High pressure?

If you want to profit from these advantages there is the necessary need for using a high pressure system. Only high pressure pumps are capable of atomizing droplets so fine that an optimal rootclimate can be created. NASA recommends a droplet size of 30 to 100 micrometers. Also the years of testing in the KKfarming labs have shown that best results are achieved with a droplet size of 65µm as it is done in the Aerobox. Furthermore it is utterly important that watering of the roots happens only by this fog. If roots are growing into the water reservoir or if they get somehow watered all the time its no longer aeroponics but hydroponics. Therefore a separation of root container and water reservoir is necessary.

Nutrient solution

The right composition of your nutrient solution is a requirement for relaxed gardening. This composition varies and is depending on different factors like the type and strain of the plant, additional lighting and the chosen location. This is why this three properties of the water solution should come to your attention:

- Temperature
- pH
- EC value (fertilizer concentration in water)

Temperature

The ability of absorbing oxigen is highly dependent on water temperature, therefore it should never get too warm. For a lot of plants the optimal value is aproximately between 17 and 22 °celsius. Increased problems mostly occure when temerature rises over 25/26°cesius.
If you should have problems with high water temperature we suggest the use of waterchillers. Also certain light sources emit a lot of heat so the use of modern LED lights can be very benefitial.

pH-level

The pH-level in a nutrient solution shows if it is more alcaline or acidic. The ability of the plant to take in nutritions is dependent on this parameter.

Regular measures and regulation of pH-level is of most importance in aeroponic systems, because as the word "Aero" already tells, in those systems the roots are hanging free in air. Unlike other growing methods like soil or in smaller extent in hydroponic (rockwool, coco, etc. ...), air does not buffer pH-levels. This has advantages and disadvantages:

+ The gardener has absolute control over his plants. The pH-level does not get falsified and can be regulated to exact values.

- With the absence of pH buffering mediums aeroponics does not allow for any mistakes. Its most important to keep the pH level of the nutrient solution in optimal range all the time.

Which pH level is the right one?

In Aeroponic growing its recommended to set pH levels a little lower than in hydroponic systems. In trying different levels of pH you will get a feel for the right settings over time. There is a broad variety of products for lowering the level of pH which most of them consist of phosphoric acid. For increasing pH-level one can simply use tap water.

Tip:

We have had good experiences with a pH value in the range of 5.2 - 5.5! Moreover we recommend to let the level oscillate in this range.

(decreasing pH-level: set pH to 5.5, when it drops to 5.2 upregulate again with tap water

increasing pH-level: set pH to 5.2 and when it rises to 5.5 downregulate again with (phosphoric) acid).

Recommendation:

We had good experiences with pH-minus from Advanced Hydroponics.

EC-level (Concentration of fertilizer in Water)

The EC-level show us the electric conductivity of a liquid, which tells us about the concentration of fertilizer in our nutrient solution. Low nutrient concentration cause deficiencies and slow the growth and development of the plants, too much nutrients on the other hand lead to burns and damages the plants.

The need for nutrients oscillates in the lifetime of a plant. In the beginning there is no need for additional fertilizer, however the ec-level of your tap water should be considered:

We recommend tap water EC-level of 0.3 to 0.5mS/cm(millisiemens per centimeter). If this value is lower, this often leads to an oscillating pH-level. (This happens because of the carbonate hardness of the water. Above all magnesium and calcium play a roll in this.)

As the roots start to grow out of the net pots, you should begin to add liquid fertilizer. By increasing the concentration of fertilizer and by observing the developement of the plants over a period of a few days you can find out about the individual EC-level optimum.

The EC-level strongly depends on the type of plant and its current developement phase. this means that general recommendations have to be given with caution. Nevertheless we also want to share our experience about Ec-level:

Tip:

A lot of plants in aeroponic systems do really well when Ec-levels are set between 0.6 and 1.2 mS/cm!

EC-level example from cutting to grown plant:

Choice of fertilizer

When choosing a fertilizer it is most important that it does not clog the nozzles and that it easily dissolves in water. Mineral fertilizers usually do better than organic ones in aeroponic systems but of course you can use organic or mixed fertilizers too if preferred.

Recommendation:

We had great success with the products of Canna and Metrop.

Watering Cycle

Aeroponic system should only be watered in intervals. This is why you must use a precise timer like the seconds interval timer from our kkonline shop. You can find out whats the perfect ON/OFF interval for your plants by changing the intervals in small steps whilst observing the reaction of the plant. As rough guidline we suggest a base interval of 15sec ON/15min OFF.

Cleaning

We suggest to clean the Aeroponic system every time before a new grow starts. If there were no special occurences like pests etc. in the last grow its enough to clean the system with clear water. Whilst cleaners for aeroponic systems do exist be aware that a lot of chemicals could have negative impact on organisms in the Aerosystem.

Recommendation:

We had good experience cleaning our system with citric acid.

Hydrocorrels can be soaked in water with enzymes after root residues have been removed. Then they can be reused many times. Enzymes help to break down organic residues (e.g. root remains).

Tip:

After drying you can clean the used Hydrocorrels easily with a vacuum cleaner. Just attach a net pot on the end of the vacuum cleaner so that the Hydrocorrels don't get sucked in.

Mycorrhiza, BioFilter and CO

With the use of positive bacteria or the vaccination of mykorrhiza, nutritional intake can be upped once more. High pressure areoponic systems create perfect living conditions for mykorrhizal cultures and such. High humidity and a lot of fine roothair is an attractive combination for mykorrhizal-fungi which enlarge the surface of the roots and support the nutritional intake. Furthermore a colonization of the roots from symbiotic fungi gives other and perhaps harmful organisms a hard time to thrive. Also we would suggest to use a biofilter within your system. These filters (also used similarly in the field of aquaristic) break down organic pollution and make them available for the plants. In this way they clean the nutrient solution and stabilize it additionally. Meanwhile different manufacturers offer a vartiety of mykorrhiza spores and posive bacteria like Trichoderma species as well as endo- and ectomykorrhiza.

Measuring devices

When operating an AeroBox (or any other aeroponic system) the use of special measurment devices is essential. Especially ph and Ec levels have to be adjusted to the needs of the plant you are cultivating. Temperature of nutrient solution and room temperature should be monitored as well.

Values to be monitored:

- Temperature
- pH-level
- EC-level

We recommend a combined pH and EC measuring device which can stay in the nutrient solution (all around the clock), such as devices offered from companies like KKmoon or bluelab. (multi-Parameter or Guardian Monitor). Sample checks are sufficient too but do not use ph test strips for they are not accurate enough and therefore not suitable. Measuring devices should be able to display parameters with at least one decimal place. (e.g. 5.2 pH, 0.8 EC).

We hope that this guide helps and makes it easier for you to getting started with aeroponic systems. If you have any question do not hesitate to contact us, we are glad to help wherever we can.