How aeroponic and bubble cloners work, how to set one up, buying vs DIY, and the pitfalls (heat, dirt, power loss) that wreck a cloner. Honest, no upsell.
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Aeroponic Cloning for Cannabis: Cloner Setup, Use, and Pitfalls
A customer came in furious at his aeroponic cloner. For two rounds it had rooted clones in a week with near-perfect success, and then a batch turned to slime and died on him completely, so he was convinced the machine was junk. A few questions told the real story. His grow room had been running warm, his reservoir was murky because he had not cleaned it between rounds, and there had been a brief power flicker overnight. None of that is the machine's fault, and all of it is exactly how aeroponic cloners fail: fast, and all at once. We did not sell him a new cloner. We told him to clean it properly, keep the water cool, and for his small batches consider a fifteen-dollar tray of cubes that does not care if the power blinks.
That is the honest frame for this guide. An aeroponic or bubble cloner is the fastest way to root cuttings at volume, and when it is dialed in it is genuinely impressive, often rooting clones in seven to ten days with no medium and no hormone. But it is also the least forgiving method on the shelf, because a bare stem suspended in water has no buffer: get the temperature, the cleanliness, or the power wrong and you can lose an entire tray in a day. This article explains how these cloners actually work, how to set one up and run it, whether to buy one or build one, and above all the pitfalls that turn a star performer into a disaster. We sell cloners and the parts to build them, and we will also tell you when a tray of cubes is the smarter buy. We don't upsell. For the fundamentals of taking a cutting, start with our step-by-step guide to cloning cannabis.
The 30-Second Answer
An aeroponic cloner roots bare cuttings by constantly misting or bubbling their stems in oxygen-rich water, with no growing medium at all.
- Why growers love them: fast (often roots in 7 to 10 days), high success at volume, no medium to buy, reusable, and clones transplant with bare clean roots.
- The catch: they need electricity, so a pump or power failure can kill a whole tray quickly; they must be kept clean and cool or they breed root rot; and they are overkill for a handful of cuttings.
- To run one: clean it, fill with plain pH-adjusted water kept cool (around 65 to 72°F), insert fresh cuttings into neoprene collars, run the pump, keep it covered with gentle light, and expect roots in one to two weeks.
Honest bottom line: a cloner is brilliant for speed and volume. For a few clones a couple of times a year, a tray of rooting cubes is cheaper, simpler, and survives a power outage.
What an aeroponic cloner is and how it works
An aeroponic cloner is a sealed reservoir with a lid full of holes, each holding a soft neoprene collar that grips a cutting so its bare cut stem dangles in the empty space inside. A pump then keeps those bare stems constantly wet with oxygenated water, either by spraying them with a fine mist (true aeroponics) or by vigorously bubbling an airstone to throw oxygen-rich water around the chamber (a bubble cloner). There is no rockwool, no plug, no coco, just the stem, water, and air.
The reason this roots so fast comes straight back to what a cutting needs. A rooting cutting requires moisture and oxygen at the same time, and a cloner delivers both in abundance: the stem never dries out, and because it is suspended in air and hit with aerated water, it gets far more oxygen than it would buried in a soggy medium. As UNH Extension's propagation guidance explains, the propagation environment has to supply both moisture and oxygen to the developing roots, and a cloner essentially maximizes both at once. That is why clones in a good cloner often root noticeably faster than the same cuttings in a medium, and why many growers skip rooting hormone entirely in a cloner, though a quick dip does not hurt. There is also a running-cost angle worth noting: a cloner uses no consumable medium, so after the upfront purchase you are mostly paying for a little electricity and the occasional replacement part, which is part of the appeal for growers who clone constantly and would otherwise keep buying trays of cubes.
The same design that makes a cloner fast is also what makes it fragile, and understanding that tradeoff is the key to using one well. A bare stem in water has no medium to hold a reserve of moisture, buffer the temperature, or slow the spread of pathogens, so the machine has to keep doing its job continuously. When it does, you get fast, clean roots. When it stops, or when the water turns warm or dirty, there is nothing to protect the cuttings, and they fail quickly.
Aeroponic cloner vs bubble cloner vs a tray of cubes
Before you buy or build anything, it helps to see the three common approaches side by side, because the fastest option is not automatically the right one for you. A true aeroponic cloner uses a pump and spray manifold to mist the stems, and it is the fastest and usually the priciest, with the most moving parts to maintain. A bubble cloner skips the misters and simply runs an airstone to bubble and churn oxygenated water against the stems; it is nearly as effective, far simpler, and cheap enough that many growers build their own, which is exactly why it is the most popular DIY route. A tray of rooting cubes is not a machine at all, just cuttings stuck in rockwool or starter plugs under a dome, and while it roots a little slower, it is the cheapest, simplest, and by far the most forgiving option, with no pump to fail and no power required.
The honest way to choose is by your scale and temperament, not by chasing speed. If you root a lot of clones often and value getting them rooted fast and uniformly, a cloner pays off. If you want cloner-like results on a budget and do not mind a little assembly, a bubble cloner is the sweet spot. And if you take a handful of cuttings now and then, or you simply do not want one more thing that can break and flood, a tray of cubes will serve you better and cost almost nothing. The medium route is covered in depth in our guide to rockwool vs Rapid Rooter vs coco, so this article focuses on the machines.
Is a cloner just active water cloning?
In a sense, yes, and it helps to see it that way. The simplest possible clone is a cutting stuck in a glass of water on a windowsill, which often roots on its own because the stem stays hydrated. The problem with still water is that it goes stale and low in oxygen, which slows rooting and invites rot. An aeroponic or bubble cloner solves exactly that by keeping the water constantly moving and aerated, so it is essentially still-water cloning with the oxygen problem engineered out, which is why it roots so much faster. It is also closely related to how a deep water culture system works, where roots live in oxygenated water, so if you grow in DWC or another hydroponic setup, a cloner feeds naturally into your system, since the rooted clone is already adapted to living with its roots in water.
Buying a cloner: what actually matters
If you decide a machine is right for you, a few things matter far more than the marketing. Build quality and the pump come first, because the pump is the heart of the machine and a cheap one that fails is what kills trays; a reliable pump and a well-sealed reservoir are worth paying for. Ease of cleaning is the next most important and the most overlooked, since you will clean this thing constantly and a design that is a pain to scrub is a design you will neglect. Site count should match your real needs, as a giant unit is harder to keep clean and is wasted if you only root a dozen cuttings at a time. You will see established machines such as EZ-Clone on the premium end and budget aeroponic units like the Clone King at the value end, along with various bubble-style cloners; the same logic applies across all of them, so match the size and price to how you actually clone rather than buying the biggest one. It is also worth a look at the dome and collars: a snug humidity dome and good-quality neoprene collars that hold cuttings without pinching make day-to-day use easier and rooting more consistent, and they are cheap to replace as they wear.
Buy a cloner if
You root clones frequently or in volume, you want the fastest and most uniform rooting, and you are willing to keep it clean and protect it from heat and power loss.
Skip a cloner if
You only take occasional cuttings, you want the lowest cost and least maintenance, or you do not want to depend on a pump and the power staying on. A tray of cubes is the better tool.
Building a DIY bubble cloner (cheap and effective)
One of the worst-kept secrets in cloning is that you can build a bubble cloner that rivals an expensive machine for a fraction of the price, which is why DIY cloner builds are so popular. The recipe is simple: a lidded tote or bucket for the reservoir, an aquarium air pump and one or two airstones to oxygenate and churn the water, and a set of neoprene collars seated in holes or net pots in the lid to hold your cuttings with their stems hanging into the chamber. Fill it with plain pH-adjusted water so the airstones keep the stems splashed and the water oxygen-rich, and you have a working cloner for the cost of a few parts.
The performance is genuinely close to a commercial unit for small to medium batches, and the build is forgiving as long as you follow the same rules as any cloner: keep it clean, keep the water cool, and make sure the air pump keeps running. The main practical difference from a misting aeroponic machine is a slightly slower and sometimes slightly less uniform root, which for most home growers is a non-issue next to the cost savings. We stock airstones, air pumps, neoprene collars, net pots, and reservoirs if you want to put one together, and we are happy to help you spec a simple build.
How to set up and run a cloner, step by step
Whether you bought a machine or built one, the routine is the same, and getting it right is mostly about water, temperature, and cleanliness.
Start by cleaning and sterilizing the entire unit, the reservoir, lid, collars, pump, and any misters or airstones, before every run, not just the first. Fill it with plain water adjusted to a slightly acidic pH, generally in the 5.5 to 6.0 range, and keep that water cool, because temperature is critical. Cool water holds more oxygen and discourages pathogens, and propagation guidance is clear that the rooting zone should not be allowed to run warm; Greenhouse Product News notes that propagation conditions are managed to keep the rooting environment cool and humid, and most cuttings root within roughly two to three weeks under good conditions. Aim to keep the reservoir somewhere around 65 to 72°F.
Next, take healthy cuttings with a clean, sharp blade, cutting just below a node, and insert each one into a neoprene collar so the cut stem hangs into the chamber. Seat the collars in the lid, close it up, and switch on the pump so the stems are continuously misted or bubbled. Keep the cloner under gentle light, not intense flowering light, and put it somewhere stable and cool. From there it is mostly waiting: top off the water as needed to keep the stems reached by the spray or bubbles, peek for roots after about a week, and once you see a healthy set of white roots, move the clones into their next home. Because cloner roots are bare and a little fragile, transplant them gently and keep humidity up for a day or two while they settle.
The pitfalls that wipe out a cloner
This is the part that matters most, because an aeroponic cloner does not usually fail slowly with a few weak clones. It fails all at once. Here are the pitfalls that turn a 95 percent cloner into an empty tray, and they are almost always the real reason a cloner stops working.
Heat is the number one killer. When the reservoir water gets warm, it holds less oxygen and becomes a breeding ground for the pathogens that cause root rot, and you can watch healthy cuttings turn to brown slime in a day or two. According to Michigan State University Extension, warm, waterlogged conditions during propagation invite rot, and a warm cloner is the most waterlogged environment there is. Keep your room and your reservoir cool; a cloner in a hot tent is a cloner on borrowed time.
Dirtiness is the close second. A bare-stem system has nothing to slow the spread of disease, so a reservoir left dirty between runs builds up biofilm and pathogens that rot the next batch. As University of Minnesota Extension notes, the organisms that cause cuttings to rot and turn mushy spread readily in standing water and on dirty tools and equipment, which is precisely the cloner's environment if you neglect it. Sterilize the whole unit between every single run, and use clean blades and hands when you take cuttings.
Power and pump failure is the silent disaster. Because the cuttings rely on the pump running continuously and have no medium to fall back on, a pump that quits or a power outage that stops the misting can let bare stems dry out or crash within hours. A blackout overnight can cost you the entire tray. If you run a cloner, consider a backup such as an uninterruptible power supply or a battery air pump, check that the pump is actually running each day, and understand that this dependence on power is the single biggest reason a tray of cubes, which needs no electricity at all, can be the more robust choice. If your clones are failing and you want to diagnose why, our guide to why clones fail to root walks through rot and the other usual causes, and keeping the room itself stable is easier with our VPD chart and ventilation guide.
Overcomplicating the water is the last common trap. Growers pour enzymes, additives, and proprietary cloning solutions into the reservoir chasing better results, when plain clean cool pH-adjusted water is what actually works, and the extra products often just feed problems. Keep it simple.
Cleaning and maintaining your cloner between runs
Since dirtiness is one of the top ways a cloner fails, a real cleaning routine is not optional, it is the maintenance that keeps the machine working. After each batch, empty the reservoir and scrub every surface that touched water, the tank, lid, collars, and spray manifold or airstone, to remove the slimy biofilm pathogens live in. Many growers run a sanitizing rinse, such as a diluted hydrogen peroxide solution or a manufacturer-recommended cleaner, through the system, then rinse thoroughly with clean water before the next run. Check and clear the pump and any spray nozzles, since clogged misters are a common reason an aeroponic unit suddenly underperforms, and replace airstones periodically as they clog. During a run, watch the water level and top it off so the stems stay reached, and on a longer batch a partial water change keeps things fresh. None of this is difficult, but it is the difference between a cloner that roots reliably for years and one that crashes every third batch. The growers who never clean their cloner are usually the ones who conclude, wrongly, that the machine itself is unreliable.
Do you need rooting gel or additives in a cloner?
Mostly no, and this is where a lot of money gets wasted. Because a cloner already bathes the stem in oxygen and moisture, cuttings frequently root with nothing added at all. A quick dip in a rooting gel before you seat a cutting will not hurt and can speed things slightly, so it is fine if you like using it, but it is not required, and whether it is worth it is its own question we cover in our comparison of Clonex vs Olivia's vs Dip 'N Grow. What you should be wary of is pouring enzymes, nutrients, and proprietary cloning additives into the reservoir, a common habit that tends to cause more rot and biofilm than it prevents, since a rootless cutting cannot use much nutrition anyway. Clean, cool, pH-adjusted water is the proven base, and additives are at best optional and at worst the source of the slime you are trying to avoid. If you feel the urge to add something, add a habit instead of a product: clean the reservoir between runs, check the water temperature, and confirm the pump is actually running. Those three free habits will do more for your success rate than anything you can pour into the tank.
Do you even need an aeroponic cloner?
Here is the honest gut-check before you spend the money. Cannabis is an easy-rooting plant, and it roots perfectly well in a cheap tray of cubes under a dome, no electricity required. An aeroponic cloner earns its place when speed and volume genuinely matter to you, when you are rooting many cuttings on a schedule and a few extra days or a few extra failures per batch actually cost you something, or when you simply enjoy running a more active system and will maintain it properly. For a grower taking a dozen cuttings a couple of times a year, a cloner is more cost, more maintenance, and more risk than the job requires, and a tray of cubes will quietly outperform it on convenience and reliability. It is also worth matching the tool to your grow style: a perpetual or staggered setup that needs a steady trickle of rooted clones suits a cloner kept always running, while a grower who clones in occasional bursts gets less from a standing machine. That is not a message you will hear from a company that only sells machines, but it is the truth, and it is why we will point you to the cheapest tool that fits your grow. We don't upsell.
What We'd Tell You at the Counter
If you set a cloner on the counter and asked whether to buy it, we would first ask how many clones you take and how often. Lots, often, and you want them fast, then a cloner is a great tool, and a bubble cloner gets you most of the way there for a fraction of the price of a misting machine. A handful now and then, and we would steer you to a tray of cubes, because it is cheaper, simpler, and does not die when the power blinks. Whichever you choose, the rules never change: clean water, cool temperature, a pump that keeps running, and no fancy additives. Keep it cool, keep it clean, keep it powered, and a cloner will reward you with the fastest roots in the building. Neglect any one of those and it will fail all at once. We stock the cloners, the parts to build one, and the cubes if a machine is more than you need, and we will tell you honestly which is which. We don't upsell.
Frequently asked questions
How does an aeroponic cloner work?
It holds cuttings in neoprene collars in the lid of a sealed reservoir so their bare stems hang into an empty chamber, then a pump constantly mists the stems (true aeroponics) or an airstone bubbles oxygen-rich water against them (a bubble cloner). The constant moisture plus high oxygen triggers fast rooting with no growing medium, which is why clones often root in one to two weeks.
How long do clones take in an aeroponic cloner?
Often faster than in a medium, frequently around seven to ten days for a misting aeroponic cloner and roughly ten to fourteen for a bubble cloner, though it varies by strain and conditions. The constant oxygen and moisture speed things up, but rooting still depends on healthy cuttings, cool clean water, and a stable environment. Most cuttings root within about two to three weeks under good conditions.
Aeroponic cloner vs bubble cloner: what's the difference?
Both root bare stems in oxygenated water with no medium. A true aeroponic cloner uses a pump and misters to spray the stems and is usually fastest and priciest with more parts to maintain. A bubble cloner uses an airstone to bubble and churn the water instead, which is simpler, cheaper, and easy to build yourself, at the cost of slightly slower and sometimes less uniform rooting. For most home growers the difference is minor.
Do you need a cloning machine to clone cannabis?
No. Cannabis roots readily in a simple tray of rockwool or starter plugs under a humidity dome, with no machine or electricity. A cloner is worth it mainly for speed and volume, so if you root many clones often it pays off, but for occasional cuttings a tray of cubes is cheaper, simpler, and more forgiving.
What water temperature should a cloner be?
Keep the reservoir cool, generally around 65 to 72°F. Cool water holds more dissolved oxygen and discourages the pathogens that cause root rot, while warm water does the opposite and is the leading cause of a cloner crashing. If your room runs hot, managing reservoir temperature becomes the most important thing you do.
Why are my clones rotting in the cloner?
Almost always warm water, a dirty reservoir, or both. Warm, dirty water is low in oxygen and full of the organisms that rot stems, so cuttings turn brown and slimy fast. Sterilize the entire unit between runs, keep the water cool, use clean tools, and avoid piling in additives. A pump that has quit, leaving stems without moisture, can also cause sudden failure.
Can you build a DIY bubble cloner?
Yes, and it is one of the best-value projects in cloning. You need a lidded tote or bucket, an aquarium air pump with one or two airstones, and neoprene collars or net pots in the lid to hold the cuttings. Filled with plain pH-adjusted water, it performs close to a commercial machine for small to medium batches, as long as you keep it clean, cool, and powered.
If a cloner is right for you, the aeroponic and bubble cloners, plus the air pumps, airstones, neoprene collars, net pots, and reservoirs to build your own, live in the Modern Farms catalog under Plant Care and Environmental Control, and our team is happy to help you spec a machine or a DIY build that fits your scale, or point you to a simple tray of cubes if that is the smarter buy. For where cloning fits in the full grow cycle, the week-by-week cannabis grow guide maps the timeline. Because, as always, we don't upsell.
For informational and educational purposes only. This article is general horticultural guidance and is not legal advice. Cannabis cultivation laws vary by country, state and locality, and growing cannabis may be illegal where you live. Always understand and comply with the laws and regulations that apply to you before propagating or growing any cannabis plant.