Frequently asked questions about aeroponic cuttings / aeroponic propagation / taking and maintaining clones in an aeroponics system
Here are some of the most common questions about aeroponic cloning. If your question is now answered, please let us know below and we’ll add it to the list!
1) What kind of water should be used initially to fill the res? Is regular tap ok? Or should I use distilled? Any need to pH adjust the water initially?
Regular tap water is typically fine in most major areas. It’s what we always recommend trying first. Distilled or reverse osmosis water should NOT be used, as it’s so stripped of any type of mineral content that it pulls important minerals from the plant tissue hindering the initiation of root development. We recommend users run their system without cuttings in it for the first 24 hours if they have the time. This allows them to check what their temps will be and allows some time for pH stabilization. Water should be pH adjusted after any types of solutions are added and adjusted again after cuttings have been inserted. Fill the cloning machine as high as you can so that the water level is just below the misters. The more water that is in the res, the more stable the pH and temperature.
2) Do you recommend adding anything to the water?
Yes. Use a rooting stimulator – check the label but 1 teaspoon per gallon is a general guide. Also, consider adding a silica product – this will assist in building strong cell walls and protect against bacteria etc.
3) What about adding some mineral nutrition? Should growers wait until they see roots developing? How much? And what sort of strength / pH?
Add nutrients only after roots have developed to between 3-4 inches in length. Use mineral (hydroponic) nutrients as they keep the reservoir cleaner. Stay between 400-500 ppm for new clones after root development. pH between 5.8-6.3. 5.8 is ideal. Even without the use of any additives, the pH of tap water will have a tendency to rise over the course of 24-48 hours. To compensate for this, try adjusting the initial pH down to approximately 5.2 because you know the pH will slowly rise somewhere close to between 5.8 and 6.3. This is an acceptable range for getting quality results. Keep the closest eye on pH during the first 24-48 hrs. If the pH needs to be adjusted again later on, do so, but it usually stables out after the first few adjustments. If you are not sure if you’ve got an accurate pH reading, invest in a quality digital pH meter.
4) Veg or bloom nutrients? Something with phosphorus (for rooting) and nitrogen?
As long as you’re taking cuttings from a healthy mother plant (and what else would you take cuttings from?) there’s really no need to use nutrients during the cloning process. A cutting is developing roots because it’s searching for food. If you try to feed something that doesn’t have a mouth yet, you’re defeating the purpose. Cuttings root perfectly fine with some IBA’s and Vitamin B-1.
5) Can you explain how “rootless cuttings” are still able to uptake water, with no need for humidity dome? We’ve seen it with our own eyes, just wondered if there’s a scientific explanation.
The plant tissue still absorbs a sufficient amount of moisture for the cutting to sustain itself upright. Roots develop because the cuttings are searching for food. Humidity domes are NOT necessary with aeroponic cloners. In fact, I suspect domes help to promote airborne bacterias such as powdery mildew and prevent the cutting from transpiring naturally.
6) What are the general signs that a cutting is ready to leave the machine?
It depends what medium you’re transplanting into. I prefer to let the roots get 6-8 inches in length before transplanting into soil, coco, hydroton clay rocks, or other aeroponic systems.
The longer the roots, the better chance of your cutting surviving after its been transplanted.
When res temps get above 80 degrees, cuttings are more prone to pathogens and bad bacteria. Slightly off color can be ok. If you start getting greyish/brown slime cover the bottom of your cuttings, it’s time to take precautionary measures.
7) Any general tips for transplanting aeroponic cuttings into media?
The longer the roots, the better. It’s always ok to cut excessive root growth off with sterile scissors if you’re trying to transplant a cutting into a rockwool cube or other similar medium. Most people don’t understand that this will NOT kill the cutting. Just make sure scissors are clean and always be delicate when transplanting.
8) Have you heard of growers using cloches / domes to reduce transplant stress?
Only when cuttings come from cloning methods where domes were used. When they’re cloned without domes, they transplant into domeless mediums MUCH easier.
9) Pumps on 24/7 or intermittently?
You can keep your water temperatures coolest by switching the pump on a half hour on / half hour off via a segmental timer. Many growers report seeing even better results this way.
10) Is it necessary to change out the reservoir during one cloning cycle?
No, if everything is in proper working order, you should be able to continue using the same water for 4-6 weeks.
Source: JUST4GROWERS, (http://www.just4growers.com)