Ever thought about hydroponic systems for cannabis and ditching the soil in your next indoor grow? Soilless growing, AKA hydroponics, is a more advanced concept since it’s all about using a different kind of growing medium: water.
Growing with water instead of soil has a lot of advantages, which is why many things are grown hydroponically these days – tomatoes, lettuce, cucumbers, and of course, grade-A bud. Some of the best weed of our time is cultivated with hydroponic systems, so why not give it a shot?
Whether you’re new to hydronic growing or you want to take your soilless grow op to the next level, this guide to hydroponic systems can help you to harvest potent bud and high yields.
What are the pros and cons of hydroponics?
Before investing in a new hydroponic system, it’s really important that you weigh the pros and cons. Like we mentioned already, this is a more advanced type of indoor growing, so it’s not for everyone.
Advantages of Hydroponics
The first advantage of hydroponic growing is the potential for higher yields. Most hydro growers brag about the massive buds they harvest, and they usually have a right to brag.
The main explanation for higher yields with growing plants in a water solution is easier access to nutrients. We’ll get into the details on this later, but the plant roots are able to drink up nutes more effectively in the nutrient-rich water than in soil.
The second major advantage of installing a hydroponic system is faster growth. Hydro plants usually grow 30-50% faster than plants in soil pots. Again, the main reason for that is the easier access to the nutrient solution.
What are the disadvantages of hydroponics?
If growing weed on an extreme budget is your MO, hydroponic growing might not be the right choice for you. Setting up a hydro grow op isn’t cheap, especially if you go for high-quality equipment for hundreds of plants.
Another disadvantage of going hydroponic is that your plants won’t get any natural nutrients from the soil, because there isn’t any. Quality soil contains a lot of key microbes, so you’ll have to replace these with artificial nutrients.
The last con is that hydroponic systems for cannabis are more advanced and the plants/overall system needs more supervision. If you’re dedicated to your grow op and have harvested weed before, no worries. But most first-timers start with soil growing and then move on to hydro once they’re comfortable.
How does hydroponics work?
You may wonder ‘how does hydroponics work’. The word hydroponics literally translates to “working water”, which should give you a pretty good idea of how this system operates. Water is constantly working and moving in a hydroponic grow op, delivering oxygen and nutrients to the plant root systems.
What many people don’t realize is that soil isn’t actually a crucial element to growing. The soil just serves as a medium for delivering food and water. In hydro, plants can get their food and water much easier since the roots don’t have to use energy to pull what they need from the soil.
Cannabis plants still perform photosynthesis the same way with hydroponic growing. The only real difference is the way they get the food, water, and oxygen to perform photosynthesis.
The specific way your hydroponic system will work depends on the method you use. There are 4 main ones to choose from:
- Ebb and Flow
- Drip System
- Deep Water Culture
Ebb and Flow (Flood and Drain) Hydroponic Systems
Ebb and flow (AKA flood and drain) hydroponic systems work by flooding the grow area with nutrient-rich water at timed intervals. After the water floods and plants get their nutes, it then drains back out into a reservoir that contains a pump set up on a timer.
Unlike other setups, the roots aren’t always submerged in an E&F/F&D grow op. The water literally ebbs and flows in this hydro grow system.
Advantages of an Ebb and Flow System
One of the biggest advantages of an ebb and flow system is that it allows for periodic feeding. Since the roots aren’t always submerged in water, growers have easier access to plant root systems when there’s no water in the plant tray.
It’s a go-to option for beginners since set up is fairly straightforward. There are just four basic components of an ebb and flow system: the reservoir with nutrients, a flood tray, a submersible water pump, and a timer. That’s it.
Ebb and Flow Hydroponics Set Up
To set up an E&B hydroponic system, you’ll first need to gather up your supplies. If this is your first time, try to keep things simple – you can always get more advanced and add in more components after your first go-around with it.
There are a lot of different ways to set up an ebb and flow grow room, but for a basic setup, you’ll need:
1. Tray Table
For your plant table, a large shallow container is best. This is where you’ll place your plants and where water will be pumped in from a reservoir below.
Botanicare Grow Tray
2. Growing Medium
You’ve got a few options for growing media, but rockwool works really well for ebb and flow and you can begin your grow with rockwool “starter blocks”. These are great for clones and seeds, then as your plants develop you simply insert these starter blocks into the hole of a larger block. Another option is loose “grow” rocks, which are small clay pebbles.
3. Water Tank Set-Up
For your water tank, you can use a large plastic bin from Home Depot. You’ll also need a high-quality submersible pump to move water in and out of the tank, fill/drain fittings, and some tubing for the water to move through as it makes its way from the tank reservoir to the tray table.
Water Tank Components
The last piece of the puzzle for setting up the water tank is a pump timer. Choose one that’s super reliable and has good reviews, and invest in a backup if you can. It’s also a good idea to get an air stone to keep water moving while plants are being fed.
UKOKE Pump Timer
Drip System Hydroponics
A drip hydroponic system works in a similar way to drip irrigation used for soil growing. A large tray table is filled with the growing medium of your choosing (clay pebbles work great) and the plants are placed directly in the medium.
Each plant is set up with its own drip pipe, where water will continuously be fed through at a slow pace from an external water tank that has a pump and air stone to keep things moving. As the water drips through the plants, all excess runoff will drip down from the medium into a wastewater tank.
Advantages of a Drip System for Cannabis
A lot of growers consider drip systems the best hydro option. It’s not necessarily the best for beginners since setting it up takes some work, but it’s really popular among commercial growers since it supports larger plants.
How to Build a Hydroponic Drip System
Although the setup is different, you’ll need all the same parts and pieces for a drip system as you would for an ebb and flow. These are the main steps if you want to grow hydroponically using a drip system:
- Set up tray table, growing media, plants, and water tank with pump.
- Make sure that the runoff is set up to go into a separate waste tank instead of draining back into the main tank.
- Add drip lines to the pump and plants. For optimal growth, you want at least 15% runoff (if 1-liter water gets dripped in, 0.15L should come out the bottom).
The best way to set this all up is to use a garden irrigation kit, which will usually come with everything you need except for maybe the tray table and grow medium.
Podoy Drip Irrigation Kit
Deep Water Culture
Like ebb and flow, installing a deep water culture hydroponics system is a great starting point for beginners. It’s a low maintenance system that’s relatively easy to set up, plus it’s usually the cheapest way to get a hydroponic system up and running.
In a DWC system, plants are permanently suspended in a water tank. To make sure the plants get enough oxygen, the water is aerated, usually just with a simple air stone connected to an external air pump.
How to Use a Deep Water Culture Hydroponics Kit
Setting this up is easy, especially if you buy a DWC hydroponics system kit. These kits usually come with everything you need, including the buckets, the medium, drain fillings, air stones, tubing, hoses, and air pump.
To use a hydroponics kit, just follow the instruction for setup. That’s the other cool part about buying a kit instead of all the pieces individually; you’re given a detailed instruction manual on how to set it up.
Best Deep Water Culture Hydroponics Kit
Out of all the deep water culture kits for growing cannabis, the best is the 4 Bucket System by Grow Buckets. It comes with literally everything you need to get started, including four 5-gallon buckets filled with clay pebbles.
DWC 4 Bucket Deep Water Grow Kit
Aeroponic hydroponic growing is less common, so we’ll keep this brief. With aeroponics, the plants don’t sit in a water solution at all. Instead, they hang suspended in the air with the roots completely exposed.
How Does Aeroponics Work?
Similar to other general hydroponics systems, aeroponic setups use a large water tank, but the roots aren’t actually submerged in the water. The water is filled only to about 25%, and the roots hang over the surface.
Beneath the water tank, there’s a pump that mists nutrient rich water up into the roots. The mist is fine and constantly going.
Plants are placed into the top of a large tank of water filling the bottom 25%. Under the water is a pump that sends water into misters underneath the root systems. This fine mist constantly sprays the roots, giving plants massive quantities of air and water simultaneously.
This is considered a futuristic way of growing hydroponic plants – definitely not a beginner-friendly method.
Best Nutrients for Hydroponic Cannabis
Choosing the right nutrients for hydroponic cannabis is a major part of a successful hydro grow op. First thing’s first, always make sure to choose nutes that are meant specifically for hydro, like the General Hydroponics Calimagic & Flora Gro Micro & Bloom Combo.
General Hydroponics Nutrient Bottle Combo
Some nutrients are meant only for soil growing, and mixing these up can turn your crop into a flop. This is because plants draw specific nutrients from the soil, things like boron, manganese, and zinc. For this reason, most hydro nutrients contain more micronutrients than found in soil-based nutes.
Compared to nutrients for soil growing, here are a few more things to look for when you choose a nutrient solution for healthy hydroponic plants:
- Higher levels of nitrogen – N is abundant in soil, but not so much in the water.
- Lower levels of phosphorus – P tends to be more available in hydroponic setups than in soil.
- No organic sources of nutrients – Hydro plants aren’t able to break down organic microorganisms, so there’s more of a risk of “bad” stuff growing when nutes contain organic stuff.
- More often made with chelated minerals – These are easier for hydroponic plant roots to absorb.
Caring for Hydroponic Weed Plants
Caring for your hydroponic plants takes work and a lot of attention to detail. By detail, we mean things like pH, nutrient levels, and regular tank cleanings. Below are a few of the most common questions about caring for plants in a hydroponic grow system.
What should my pH be for hydroponics?
If you think you know all about pH from your last soil grow op, think again. The pH levels in a hydro system should be lower than when you use soil as your growing medium.
You can usually get away with a pH anywhere between 6 and 7 for plants growing in soil, but for hydro, aim to keep the water pH between 5.5 and 6.5 (6 would be ideal).
To stay on top of pH, which needs to be checked every single day, you’ll definitely want to use a digital pH pen. Our favourite is the Bluelab BLU2300E Combo meter, which is easy to use and reads both pH and PPM.
Top pH and PPM Meters Comparison Table
How often do I change my res water?
Some people say that changing out the reservoir water, AKA res water, should be done every 2 weeks. We feel that it should be done more often than; this to prevent germs and to promote healthy growth.
You can change out the water every 5 days, but always be sure to check the pH and PPM of the reservoir every single day.
How do I keep my garden in control?
Hydroponic plants grow big and they grow fast, so it’s really easy for a garden to get out of control quickly. Just like with soil-based systems, there are a few things you can do to keep the plants in control, like:
- Use trellis netting (make sure it has 6″x6″ holes) to spread plant branches.
EACHON Trellis Netting
- Trim off lower leaves with quality shears and only leave the top 12″ to 18″ of plant foliage, depending on light strength.
Fiskars Easy Action Micro-Tip Shears
- Remember, cleanliness is key. Use bleach to clean your res tank every time you refill it and always remove dead leaves, dirt, and other debris.
Whether you start out simple with a deep water culture setup or use a good old ebb and flow, hydroponic growing has some huge advantages, like fast-growing plants and big buds.
Want to grow hydroponically? Reach out to our Facebook group for more info on running the best hydroponic op possible.