[UPDATED & EXPANDED FOR 2018] Hydroponic systems can help you grow marijuana faster than using a traditional soil method. It’s harder to grow hydroponic weed, at first. But once you get the hang of it, you can achieve higher yields faster, and with less effort. However, the world of indoor grow systems can be pretty intimidating to the new grower—there’s a lot of choice on the table. So in this review and guide we’re going to take a look at the various different types of hydroponic systems available, take you through the basics of hydroponic growing and recommend 10 of the best hydroponic systems for growing cannabis.
Whether you want something simple, something that allows you to customize to your heart’s content, a hydro setup for a small grow space, or a complete grow kit, you should be able to find a cannabis grow system here to suit your needs.
Read on to learn more about hydroponic growing and hydro systems. Or you can use the table below to compare systems at a glance and skip down to the system that most interests you.
Table of Contents
- 1 Top 10 Best Hydroponic Grow Systems for Growing Cannabis
- 2 Marijuana Hydroponic Systems: The Basics
- 3 What you need to grow hydroponic marijuana
- 4 Basic overview of how to grow cannabis
- 5 Types of hydroponic systems for growing marijuana
- 5.1 Deep Water Culture, aka Hydro Pots or Bubbleponics
- 5.2 Top Feed or Drip Hydroponics
- 5.3 Ebb and Flow, aka Flood and Drain
- 5.4 Advantages of ebb and flow / flood and drain grow systems
- 5.5 Drawbacks of ebb and flow / flood and drain grow systems
- 5.6 Aeroponics with Misting (aka Fogponics)
- 5.7 Nutrient Film Technique
- 6 Best DWC Systems for Cannabis
- 6.1 PowerGrow Systems Deep Water Culture (DWC) Hydroponic Bucket Kit 5 Gallon, 6 inch – Best cheap single plant hydroponic system
- 6.2 Current Culture Under Current Solo 13 (8 in. Net Pot, 13 Gallon Grow Module) CCH2O UCSOLO13 – Best professional quality single plant grow system
- 6.3 HTG Supply Bubble Brothers 6-Site DWC Hydroponic System – Best six plant DWC grow system
- 7 Best Ebb and Flow / Flood and Drain Systems for Cannabis
- 7.1 AutoPot 4pot System Gravity Fed Watering System. Hydroponics and Traditional Gardening – Editor’s Choice: Lowest running costs, lowest risk, electricity-free
- 7.2 Oxygen Pot Systems 6 Site XL Super-Flow (Digital) – Best 6-plant ebb and flow hydroponic system
- 7.3 Viagrow V4X4COMP Ebb & Flow Hydroponic System Tray, 4′ x 4′ – Best complete ebb and flow hydroponics kit
- 8 Best Drip or Top Feed Systems for Cannabis
- 8.1 General Hydroponics Waterfarm Complete Grow System Kit – Best one plant hydroponic grow system for beginners
- 8.2 General Hydroponics EcoGrower Drip Hydroponic System – Best complete hydroponic drip system kit for beginners
- 8.3 SuperCloset Superponics-8 Hydroponic Plant Propagaton Reservoir System – Best grow system for small spaces
- 9 Best Aeroponics Systems for Cannabis
- 10 Growing mediums for hydroponics
- 11 Tips for growing healthy plants
- 12 How to test pH acid levels
- 13 How to fix pH levels that are too acidic or alkaline
- 14 How to stop root rot
- 15 Nutrients for healthy cannabis growth
- 16 Get the low down on growing weed
Top 10 Best Hydroponic Grow Systems for Growing Cannabis
Here’s our pick of the best marijuana hydroponic grow systems currently available:
Before we get to the reviews, let’s explain hydroponics in more detail. What it is, how it works and the different types of system available for growing your weed.
Marijuana Hydroponic Systems: The Basics
A quick tip to begin:
Many growers recommend practising before you try it.
For example, plant cannabis in soil and grow it that way to get a feel for it.
Or else grow something like lettuce or tomatoes hydroponically as a test run. Tomatoes especially have a lot in common with cannabis plants.
That way, you can get your rookie mistakes out of the way with a cheaper crop—it’s pretty easy to make mistakes at the start with hydro systems—and get yourself well acquainted with the system you’ve chosen.
What exactly is hydroponics?
Hydroponics is simply a method of growing plants without soil, using minerals and nutrients dissolved in water. The roots of the plants are exposed to this solution constantly or periodically, depending on the system employed.
Plants don’t need soil exactly. What they need is the minerals within it that are dissolved when it’s watered. Soil also gives support to the plant and its root structure.
So hydroponic grow systems replace soil with a grow medium that supports the plant and its roots, but more efficiently exposes those roots to the nutrient solution and keeps the roots better aerated—roots need to breathe and lack of dissolved oxygen can lead to root rot. (We’ll cover root rot in more detail later on.)
Constant exposure to the ideal amount of water and minerals means the plant can spend less of its energy growing roots in search of nutrition and more energy on growing the parts of it that matter to growers. Which all leads to fast grow times, high yields and more grow cycles per year.
Now, if you’re ready to jump in and get started with your own hydroponic setup, let’s take a look at what you’ll need.
What you need to grow hydroponic marijuana
Here are the basic things you need to raise cannabis in a hydroponic garden:
- A space for growing, like a grow tent
- Lamps that mimic sunlight
- “Soil” like coco coir or peat—or in hydroponics terms, a grow medium
- pH tester for acid levels
- PPM tester for nutrient levels (if you like to closely customize and optimize your plants’ diet)
- Timers to control the lights and pumps (usually there’s a pump)
- Ventilation if you use hot lamps like HPS and if you need to control odor
- Seeds or clones
Each plant you grow will result in one to three ounces of marijuana, depending on factors like the strain and how healthy the plant is.
Basic overview of how to grow cannabis
Whether you choose the more popular Sativa for its high, or Indica for its calming and healing power, most of the growth process is the same. You might trim the top of an Indica to make it bush out more, but the way you water and feed both kinds of plants is the same.
First, check the temperature in your grow room. The best range for cannabis is between 80 and 85 degrees F, but no more than 90 degrees.
With hydroponics you’ll also usually need to keep an eye on the temperature of the water in your system’s reservoir. The ideal temperature is between 63 to 72 degrees F. This ensures maximum nutrient uptake and enough dissolved oxygen content to keep your roots healthy and rot-free.
Second, use filtered or pure well water to avoid feeding your plants chlorine and fluoride. After adding the nutrients to the water, check the pH to make sure the solution is slightly acidic, between 5.5 to 6.5, with 6.15 being about right.
Third, follow the instructions of the light you have with regards to the proper height and coverage. Hang the light at the correct distance from the tops of the plants and make sure the light reaches out to the edges of your grow area. This is where a grow tent lined with Mylar helps reflect the light back onto the plants.
Run the light for the necessary amount of time according to the growth phase of the plant. For germination, you don’t need light. Once you have sprouts, you can run the light 18 hours a day until they reach half of their final height (which depends on the strain of weed). Then to flower, you only need 12 hours of light per day.
One or two weeks into the flowering stage, sex the plants to separate males and females. You don’t want them to reproduce if you aren’t trying to get seeds. Females get white hairs and males get balls. Yes, balls. You can’t smoke males so get rid of them. They’re only good for pollen.
About two weeks before you harvest, cut out the nutrients and only feed the plants water. This cuts down on any nutrient flavoring.
When harvesting, trim the plants with a bud trimmer or by hand and dry them. Store them in an airtight container for two weeks to a month to cure.
Now that we covered the basic way to raise cannabis, let’s look at the kinds of hydroponic system available, how they work and their relative pros and cons.
Types of hydroponic systems for growing marijuana
The main types of hydroponic systems for growing marijuana are:
- Deep Water Culture (DWC)
- Ebb and Flow / Flood and Drain
- Drip or Top Feed
- Nutrient Film Technique (NFT)
NFT is the least ideal for growing cannabis, however (see below). You’ll also encounter wicking methods, which again aren’t so good for cannabis (they struggle to provide the amounts of water large marijuana plants require), so we’ll ignore them here. And Aquaponics…
Aquaponics works by creating a very clever sort of symbiotic ecosystem, in which waste from fish provides nutrition for the plants, while the plants in turn purify the water for the fish. (Obviously the fish are kept from nibbling on the roots.) But with the addition of fish into the mix… well, that’s another thing you’ve got to learn to keep alive. So we’re not going to cover it here.
But if the idea appeals to you, you can find aquaponic grow system kits to buy.
And you’ll likely enjoy this short video from National Geographic video of a Japanese ‘kabata’ system in which huge Koi carp keep water pure for the entire village of Harie and its crops:
Deep Water Culture, aka Hydro Pots or Bubbleponics
For beginners, Deep Water Culture is cheap and easy to put together and use. A DWC setup usually has three parts:
- a bucket or reservoir where the water-based nutrient solution is stored
- another basket or mesh with peat or rockwool “soil” for the roots to grow through down to the nutrient solution
- a submerged air stone (like from a fish tank) providing air to the nutrient solution
You need one DWC unit for each plant you plan to grow. Imagine a five-gallon bucket with nutrient-rich water at the bottom, then a suspended basket filled with peat moss or clay where the weed is planted, then the air stone bubbling down inside the liquid at the bottom. The majority of the root system is constantly submerged in the nutrient solution.
Then imagine that you have more than one plant. For a multi-bucket system, all the individual buckets are linked with irrigation tubes into a single reservoir that sends the nutrient water out to feed each plant. In these larger recirculating DWC systems there isn’t an airstone in each bucket, that would be inefficient, so nozzles keep the water oxygenated as it’s pumped around the system.
Water and nutrient solution needs changing and the inside of the bucket cleaning about once a week.
Why is it called Deep Water Culture?
- First, and most obviously, because the water in the reservoir is deeper than in some other hydroponic systems. In deeper water nutrient levels stay more stable. Which makes life a bit easier—less need for monitoring.
- Second, because the majority of the root mass is constantly immersed in the water.
Advantages of a Deep Water Culture system
- Some of the largest hydro yields—plants in DWC systems tend to grow very large root systems
- Relatively low maintenance once setup—just one reservoir to monitor, though regular monitoring is recommended
- Few moving parts
- Easy to assemble
- Modular systems are easy to expand if you want to grow more
- A good system for beginners—most setups are all-in-one turnkey solutions
Drawbacks of a Deep Water Culture system
- Can be hard to maintain correct water temperature within the reservoir
- A power outage or pump failure can be fatal to your crop if you don’t catch it quickly—without oxygenation the roots basically drown
- Need to have a spare pump handy just in case
- A spare reservoir may come in handy too, if you want to purify water by leaving it to stand 2 or 3 days before a water change
- Cheap pumps can be noisy—but a good pump should have its noise levels stated
- Small DWC systems can be tricky—water evaporates more, which affects the pH level and nutrient concentration
One last tip for DWC grow systems:
Two things you need to be careful about are contamination and stagnant water. Make sure that the nutrients at the bottom of the main container are protected from light and contamination, and that the air stone doesn’t stop working.
Top Feed or Drip Hydroponics
In a drip irrigation hydroponics system the nutrient solution is slowly fed directly to the roots via a network of tubes staked into the grow medium. The solution constantly drips or is sprayed into the medium and slowly drains through the root system, ready for recycling back to the reservoir for recirculation. However, the runoff can also be run straight to waste, which is more costly and less environmentally friendly but ensures maximum nutrition and protects against fungal infections. The top feed or drip system is often also used for soil growing and can be a part of a DWC system.
Advantages of a top feed / drip grow system
- Very efficient use of water and nutrients, saving money on running costs
- Good for areas where water is scarce
- Good if you’re on a budget
- No or less need to regularly empty and replace the reservoir
- Few moving parts
- Low maintenance if you have a large reservoir that can be left to run for long periods
Drawbacks of a top feed / drip grow system
- Emitters have a tendency to clog—and you’ll usually only notice when a plant starts to wilt or show other signs of under-nutrition
- Not good for organic growing, as these are the kind of nutes that tend to build up in the emitters
- Pumps used for recirculation can go wrong, so once again you’ll need to keep a spare handy
- Timers used to control drip flow can go wrong too
Ebb and Flow, aka Flood and Drain
Ebb and Flow systems periodically soak and drain the roots of your plants. You won’t have to worry about using air stones because the water doesn’t stagnate. And the root system gets plenty of air too, as the solution ebbs away. You will need a timer if one doesn’t come with the system. Again, if your central reservoir has a parasite or imbalance problem, all the plants suffer.
Advantages of ebb and flow / flood and drain grow systems
- Fairly easy to learn to use
- Periods between ‘floods’ help prevent root rot
- Highly productive
Drawbacks of ebb and flow / flood and drain grow systems
- Water needs replacing every few days in recirculating system (so could be worth investing in a spar reservoir)
- Higher running costs, due to frequent replacement of water and nutrients—especially in a run to waste system
- Spare pump and timer needed in case of failure
- Relatively high maintenance
Use different schedules for veg and flower cycles—an extra feed during flowering. And depending on the exact system you’re using, don’t flood while the plants are ‘sleeping’.
Aeroponics with Misting (aka Fogponics)
With Aeroponics and Misting, you’ll have a rain forest-like atmosphere for the roots of your plants. Plants hang in baskets and their roots get misted on frequently, creating a fog of nutrients. This makes for really fast growth and high yields but you have to monitor everything closely. In a true aeroponics system the root misting chamber is kept separate from the reservoir, but there are hybrid systems where the two chambers are combined.
Aeroponics isn’t for beginners…
But if it’s just hydroponics that’s new to you—you’re already experienced growing cannabis more conventionally— and you’re not afraid of technical maintenance tasks like replacing pumps, hoses and misters, an aeroponics grow system is well worth getting the hang of. Aeroponics is one of the most efficient, high yielding options available.
Advantages of an aeroponics grow system
- Lowest and most efficient use of water and nutes compared to other systems—aeroponics is effectively a closed-loop recirculating system with very little water evaporation
- Fastest growing system
- Some of the highest hydroponic yields (10x more than soil)—aeroponics creates ideal root growth
- Roots constantly in contact wiht oxygen
- Very little chance of algae as no light enters the root zone
- Relatively disease-free environment
- Plants can be grown more closely together for more efficient use of space, as root networks aren’t competing for space
Drawbacks of an aeroponics grow system
- You need to be familiar with growing cannabis already so you can spot and correct any problems early
- Very small margins for error! Plants grow faster, but also fail faster when anything goes wrong
- A lot of attention to detail required
- Ideally you should have monitoring systems to alert you to problems and be able to respond to problems within an hour (that’s how long it takes for the roots to dry out and your plants start dying)
- Electricity running 24/7
- Pumps and timers can fail—keep a spare
- More technical, more moving parts than other systems
- Not great for growing in a closet or spare bedroom unless you have an extremely good isolating grow tent
Nutrient Film Technique
Nutrient Film Technique systems provide a constantly flowing shallow ‘film’ of nutrient solution in a channel at the tips of the roots system. They also often use something called a capillary mat laid in this channel. These porous mats keep the nutrient solution evenly spread. The plants get fed, but not drowned (most of the roots are constantly exposed to air), and nothing gets stagnant.
These grow systems are very efficient and low maintenance. However, many NFT systems work best for smaller plants—it can be difficult to supply sufficient support for larger plants as they grow. And it’s one of the trickier systems to set up and get right, everything is very finely balanced. It’s also more often employed by large commercial grow ops. So we won’t be covering any NFT systems in this roundup.
Now, let’s get on with some reviews…
Best DWC Systems for Cannabis
Deep Water Culture systems are simple and very effective. And often easily expandable and upgradable, once you’ve got the hang of this whole hydroponics thing. Which makes them ideal for beginner hydroponic weed growers.
PowerGrow Systems Deep Water Culture (DWC) Hydroponic Bucket Kit 5 Gallon, 6 inch – Best cheap single plant hydroponic system
PowerGrow System’s Deep Water Culture 5-gallon bucket kit is great for larger kinds of cannabis. It takes up more floor space but handles humongous strains like Big Bud and Brian Berry Cough.
The PowerGrow System comes with an FDA-approved food safe 5-gallon bucket plus basket lid, air pump, air stone, tubing, and Rockwool plugs as a growing medium.
We like this setup because it has a water level marker and a bucket drain. It comes with a 1-year warranty. One note of caution—when Rockwool is dry it’s irritating to skin. Use gloves to handle it until it’s properly moistened.
Current Culture Under Current Solo 13 (8 in. Net Pot, 13 Gallon Grow Module) CCH2O UCSOLO13 – Best professional quality single plant grow system
If you want an all-in-one DWC system for your home grow that’s worthy of a pro hydro grower, check out Current Culture’s Under Current Solo 13. It comes with everything you need. Just add water.
What makes it pro standard? Besides the commercial grow quality of components, you also get something more sophisticated than just a regular bucket DWC system. The unique Sub-Current Culture technology uses negative water pressure to keep super-oxygenated water constantly recirculating through the root system. This makes nutrients super-available to the roots, for fast growth, large plants and high yields. And keeps pH and nutrient levels consistent and reliable.
Not only that, but it’s made for easy use and low maintenance. With convenient features like porthole lids for quick inspection of the root system and drain valve to make water changes easy. You’ll also need to change the water less often than with many systems, due to recirculation. This is a system made to save you time.
Current Culture backs up the quality with a 1-year warranty and expert grower support. In fact, the extensive FAQs alone will answer most questions that might arise.
HTG Supply Bubble Brothers 6-Site DWC Hydroponic System – Best six plant DWC grow system
Self-contained DWC systems are some of the easiest hydro setups to master and maintain. And these are no exception. What sets Bubble Brothers’ system apart from similar bucket setups is the commercial quality of the air pump and air stones—and consequently the high level of oxygenation you’ll get. High oxygenation is crucial to both nutrient uptake and keeping roots healthy and rot-free.
Comes with more or less everything you’ll need, including instructions and tips. But you’ll need to get your own nutes, pH checker and pH balancers.
The only real downside is that the 6″ pots could be bigger. However, the buckets are also relatively low, so vertical space is less of an issue than for some DWC systems. Also, there’s no central reservoir, but that means that any pest or fungal problems should be isolated to one bucket. An easier way to check water levels and drain the water when changing would be great, but those are the kind of features you pay extra for. And for the price, this is an excellent system.
Great value system and ideal for beginners.
Best Ebb and Flow / Flood and Drain Systems for Cannabis
Besides Deep Water Culture systems, which are typically the simplest and least expensive, there are plenty of other ways to grow with hydroponics. Ebb and flow systems are generally more expensive to buy than DWCs, but they’re efficient, effective and environmentally-friendly. You’ll even find one system where pump and timer failure won’t be an issue—because there aren’t any!
AutoPot 4pot System Gravity Fed Watering System. Hydroponics and Traditional Gardening – Editor’s Choice: Lowest running costs, lowest risk, electricity-free
AutoPot comes with one large 12-gallon reservoir and 4 smaller pots that hold 3.9 gallons each. It doesn’t come with potting or growing medium but you can add those. AutoPot systems are also easily expandable and upgradable for growing more plants. (Check out the numerous different configurations.)
This setup is gravity-fed, so it only sends nutrients when the plant has absorbed enough in its own pot to make room for more. And it’s this gravity-feed mechanism which makes it such an interesting and attractive option.
Because the Autopot system doesn’t run on electricity, so there’s no risk of losing your crop to a broken pump or timer. No need to spend money on a spare pump or timer to keep around in case of emergencies either. An absolute minimum of moving parts. (An airstone added to the reservoir would likely improve oxygenation, mind you; but if it broke, no worries.)
Moreover, water doesn’t run to waste, so it’s pretty economical and environmentally friendly—no high water bills or wasted nutrients and no electricity consumption. And the low water consumption also makes it more suitable than many systems for areas (like California) where water’s sometimes scarce.
In short, it’s low maintenance, slightly lower risk of crop failure and the running costs are low. Which makes it a great option for beginners, stealth growers, the cost-conscious and for anyone without much time on their hands.
One thing to watch out for in this style of setup is contamination in the central reservoir. If that happens, all your plants will suffer. Also, keep an eye on the tubing, just in case it gets blocked eventually by mineral build-up or similar.
Oxygen Pot Systems 6 Site XL Super-Flow (Digital) – Best 6-plant ebb and flow hydroponic system
Oxygen Pot claim this is a premium ebb and flow indoor growing system, and we agree.
For two main reasons:
First, the US-made digital controller unit, which allows you to set and control fill and rain cycles down to the second. With adjustable float switches you can also set water levels to any height. It allows for a large degree of customization, felxibility and automation. The unit also incorporates overflow protection and comes with a 5-year warranty.
Second, those pots you see in the green buckets are made of breathable fabric. This is great for roots as it gives them even more oxygen for increased nutrient uptake. And even better, fabric pots promote a phenomenon called ‘air pruning’. When roots meet the fabric the tips that penetrate the fabric dry out, causing the root to branch off laterally away from this point. And the branching fibrous feeder roots that result from this ‘pruning’ are even better at absorbing nutrients. You end up with an extensive, healthy, super-efficient root mass—meaning big, fast growing plants and high yields.
Fabric pots are also great for temperature control and allow use of pretty much any growing medium and nutrients. Making this highly flexible system great for organic growers. (Nutes are not included.)
Finally, this system is also easily expandable in units of six.
Viagrow V4X4COMP Ebb & Flow Hydroponic System Tray, 4′ x 4′ – Best complete ebb and flow hydroponics kit
Viagrow sells a four-foot by four-foot Ebb and Flow System complete with tray and stand, potting medium, timer, pump, and tubing. The 25 pots included in the box hold one gallon each but you can replace them with larger pots. However, nutes are not included.
We should also point out, since it’s not obvious from the picture, that build quality is high. The tray table tubing is welded metal, not plastic.
One downside of the system is that it’s not ideal where vertical space is at a premium.
Best Drip or Top Feed Systems for Cannabis
Top feed or drip systems are efficient with water and nutes. And top feeding gives a great boost to plants in their early grow stages. Which is why you’ll often find top feeding combined with other hydro methods to create super-effective hybrid systems, such as the ones below.
General Hydroponics Waterfarm Complete Grow System Kit – Best one plant hydroponic grow system for beginners
General Hydroponic’s bestselling Waterfarm grow system is a simple and inexpensive top-fed hydro pot perfect for a beginner grower. Even better, you can link each one of these units into a larger configuration to grow more plants at once. Being square, they’re also easy to pack in together in tight grow spaces.
The addition of a top feed to a hydro pot gives an excellent growth burst in the first few weeks, compared to a straight DWC setup.
The GH Waterfarm comes with a 2-gallon container reservoir, a smaller basket container, clay pellets, an air stone, an air pump, nutrients (GH are renowned for their hydroponic nutes), and the necessary tubing including drip feed.
The only thing to watch out for is the pH or acid levels at the beginning as your young plants start to grow. Be sure to test and make adjustments as needed.
General Hydroponics EcoGrower Drip Hydroponic System – Best complete hydroponic drip system kit for beginners
Here’s another drip system from General Hydroponics. The EcoGrower can be used to grow up to 6 large plants. And because this is General Hydroponics everything you need is included, including the nutes. As with many kits, though, you’ll need your own pH balancing kit.
The single reservoir is an advantage over many DWC and drip feed kits, since you won’t have the hassle of refilling multiple units. Although refilling could be made a bit easier than it is. We’d also prefer larger pots.
However, we like the blue supply tube running up the side of the unit that lets you check solution levels at a glance.
For the money, this is a nice relatively hassle-free DWC/drip hybrid system. It would make an excellent starter kit for new growers—especially as it comes with clear, easily understandable instructions.
SuperCloset Superponics-8 Hydroponic Plant Propagaton Reservoir System – Best grow system for small spaces
SuperCloset are renowned for their top quality turnkey stealth grow boxes and cabinets. This is their own Superponics system, which features in a number of their products. It’s another DWC / top feed hybrid system, combining the advantages of both. Also, with effectively two systems at work, if one fails then all is not lost.
As you’d expect of a system often installed in stealth grow boxes, it’s quiet and it’s been designed to fit in small grow spaces. It’s also been designed with ease of use in mind, so water changes and cleaning are relatively easy. And it’s very quick to set up—just plug it in and add nutes and water.
We’d prefer bigger pots, but…
You have to work with the space you have—and if your space is limited this a great, high quality option. Comes with an analog timer and 3-year warranty (plus lifetime customer service). Would also be an excellent beginner option.
Best Aeroponics Systems for Cannabis
Aeroponics is probably the most efficient and high yielding hydro system. However, it’s tough for beginners and has very small margin for error. Which is why we’ve only featured one model in these reviews.
General Hydroponics RainForest 66 Aeroponic System for Medium to Large Size Plants – Best complete aeroponics grow system kit
The RainForest 66 Aeroponics System from General Hydroponics is a convenient all-in-one setup to grow your weed. It comes with a 17-gallon reservoir, a sprayer, 6 plastic containers with CocoTek liners, and a 3-Part Flora Kit. The system aerates the nutrient solution before spraying it over the plant roots.
One thing to consider is that you need to watch for parasites like aphids if you don’t have this setup isolated from pests. Another consideration is the size of the pots—they are only six inches in diameter.
But customers are happy. And all in all, this is a decent affordable aeroponics system. Relatively low maintenance too—you’ll only need to switch the water out every week to ten days.
Growing mediums for hydroponics
There are a wide variety of “soils” you can use in place of real dirt. These materials are superior choices for hydroponic growing. Let’s take a look at each kind.
Peat is a popular base because it’s cheap and loaded with minerals. The most common types you’ll see are peat moss and humus. But some hydroponic growers, for precise nutrient and pH control, will prefer a neutral substrate, adding all minerals and nutrients directly to the water.
Sphagnum moss is lightweight and it holds a lot of water. It’s more expensive than peat but it works better for hydroponics.
Coco coir is made from shredded coconut husk. Sometimes it’s formed into croutons. It’s super-absorbent and retains water very well.
Rockwool, aka, mineral wool, is spun into fibers and formed into cubes or slabs. It keeps water while letting air in to penetrate to the roots. It’s alkaline by nature, so you may need to treat it before using it.
HEC pellets don’t have any nutritional value (like moss or peat), but it works great in hydroponic systems because it drains well and lets the plant roots get oxygen. It’s heavy enough to keep young plants in place during watering.
Vermiculite is a mineral used as an additive for soil-less mixes. It holds moisture and nutrients very well. Perlite is another absorbent additive often seen mixed in with coco coir and peat. They both work in much the same way as HEC pellets.
Growstone hydroponic substrate is yet another option. Growstones are pellets of recycled glass, but manufactured to be highly porous to allow a great balance between moisture retention and aeration. They’re another reusable alternative to perlite, clay pellets, pumice—the company claims they hold 12% more air and 3 times more water than a clay pebble like Hydroton.
Tips for growing healthy plants
Use these tips from expert growers to help your hydroponic experience go smoothly.
- Water your plants every couple of days when they are young, then plan on watering them once a day when they are flowering.
- Use a hygrometer to check the moisture levels or water when the top of the potting substrate feels dry.
- Watch the leaves to see if they wilt or droop—those are indicators of too much or too little water.
- When plants are flowering, some leaves may turn yellow and drop off. Stop giving nutrients, just water, because in a week or two you’ll be harvesting.
- Harvest when one-half or three-quarters of the white hairs have turned yellowish brown and when the trichomes have gone white or yellowish.
- Late harvesting makes for more relaxing marijuana.
- When trimming, don’t leave on leaves because they don’t have much THC. Use leaves to make cannabis oil or butter.
- You can tell when your buds are dry enough because they will snap off cleanly instead of bending.
How to test pH acid levels
Having the correct amount of acidity is essential for growing healthy cannabis. The right pH means nutrients get absorbed properly. Here is a brief overview of how to test pH levels.
Soil pH ranges from 1 to 14, with 1 being very acidic and 14 being very alkaline, with 7 being neutral. The ideal for weed grown hydroponically is 5.5 to 6.5, just a little acidic. (In dirt, you’ll want between 6.0 and 7.0.)
You can test the levels in two places—the nutrient solution itself and the “soil” where the plants are growing. Use a tester pen, strips, or a liquid solution to get results. You’ll take samples of the nutrient solution or the soil and use the tester to see what the acid level is.
How to fix pH levels that are too acidic or alkaline
Don’t panic if your levels vary a little from day to day. The weed can handle it. But if you go below 5.5 or above 6.5 when you’re growing hydroponically, the consequences add up fast. It’s best to fix the levels as soon as you can.
General Hydroponics sells an easy-to-use pH Control Kit. This kit even includes a pH tester so you don’t need to buy another one.
Some experienced growers have learned how to adjust pH levels with household items like baking soda and vinegar, but we don’t recommend this for new growers.
How to stop root rot
Root rot is a problem that can quickly spread through all of your plants if they are on an interconnected system. You’ll see signs like wilting leaves that turn yellow. The roots will not look white or creamy, they will be brownish and smell terrible like mildew or rot.
You can prevent root rot by making sure you don’t overfeed or water your weed and keep roots and water solution well oxygenated. Keep water temperatures below 72 degrees. Clean your system according to the manufacturer’s instructions. Remove any dead plant matter.
You can also add beneficial bacteria to your nutrient solution. Plus, there are products called “root controls” that kill fungus and protect the roots. Some growers spray the plant roots with copper treatments or clove oil. Be careful if you use hydrogen peroxide—it’s not the best choice because it kills beneficial bacteria.
Make sure your reservoir is protected from light and too much heat. If it’s properly sealed fungus and algae has a harder time invading.
If you have many plants, you may choose to remove the affected plant and watch the others to make sure they don’t get sick.
Nutrients for healthy cannabis growth
So we’ve mentioned nutrients like a zillion times and maybe you’re asking yourself what those actually are. Our favorite at the moment is a product from General Hydroponics. It’s something that NASA uses to grow plants (but not weed) in space. It’s a favorite product for people who raise herbs for essential oils, too, because it’s all organic.
General Hydroponics General Organics Go Box
The General Hydroponics Go Box is a great assortment of organic nutrients for marijuana (and other plants). It even comes with instructions and a schedule to teach you how to use them.
The box contains pint bottles of BioThrive Grow and Bloom and 8 ounce samples of CaMg+, BioRoot, BioWeed, BioBud, BioMarine, and Diamond Black. You can try them all and see your weed grow like crazy.
Get the low down on growing weed
Check back soon for more reviews and guides. Happy growing!