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growing cannabis from seed hydroponically

Growing cannabis from seed hydroponically
1.) Get Cannabis Seeds

How to Germinate Cannabis Seeds in Hydro

We have a cannabis seedling germination page which has everything you need to know about all the different germination methods, but this tutorial is different. In this hydroponic seedling tutorial I’m going to share exactly how I do my seeds from beginning to end in a DWC/bubbleponics setup!

Just follow these instructions and you’ll end up with healthy, fast-growing plants that germinate in just a few days. It’s pretty much fail proof!

Learn How to Start Seedlings So You Can Grow Hydroponic Cannabis Plants Like This!

Supplies Needed

1.) Get Cannabis Seeds

There are a few different ways to get cannabis seeds, with the most common being ordering seeds online and growing seeds you find in weed that you buy. Learn how to research and find the right strain.

Here’s a picture showing several healthy and viable cannabis seeds

2.) Germination for Hydroponics

I’ve tried a bunch of different germination methods over the years, and the technique I prefer is for hydroponics is starting with the “Paper towel method” to germinate, putting the germinated seeds into Rapid Rooters, and installing the Rapid Rooters directly into reservoir. Lots of other germination methods as well, but this has worked best for me!

Paper Towel Method

This method is hard to mess up if you follow the instructions!

    Place your seeds ins >These seedlings were sprouted using the paper towel method!

3.) Place Germinated Seed in a Rapid Rooter

The Rapid Rooter should be cut open lengthwise

Gently place the germinated seed inside, root down

Most seedling plugs will go back into place easily, and you’ll barely be able to tell it’s been opened ?

4.) Prepare Hydro System for Its New Guest

If you haven’t put your hydroponic system together yet, now is the time! Make sure your pumps are all running, and that you’ve made a reservoir with seedling-strength nutrients. You need a home to put your new plants!

Hydro Tips & Hints

  • Air bubbles – have lots and lots of bubbles in your water reservoir. That means your air pump needs to be on all the time for the full grow. The main benefit of hydro is your plant roots are getting an unlimited amount of both water and oxygen. This is achieved by dissolving a lot of air into the water via an air stone and air pump. In order to get the fast growth, you want a lot of bubbles! A highly-oxygenated tank is also far less likely to get root rot, or suffer from other unwanted organisms growing in the reservoir!
  • Hydroguard – This supplement contains a specific bacteria that was first found in rice paddies in Japan in the 40s! It’s been common in Asia for years but only in the last several years has it been available in the US from a company called Botanicare. I highly recommend, even insist, that all hydro growers get this cheap-but-effective supplement to keep plant roots healthy!
  • Add seedling level nutrients from the beginning. A lot of growers, especially soil growers, will tell you not to add any nutrients for the first few weeks of the plant’s life. That makes a lot of sense in soil, because there are lots of nutrients contained in the soil itself for your young cannabis seedling, and giving more right at the beginning can end up giving way too much for such a young plant. However, in hydro, the only nutrients your seedling gets is what’s in the water, plus what little was contained in the seed itself. Because of that, I highly recommend giving seedling-strength nutrients to your plants from when you first fill your reservoir. Seedlings grow a LOT faster with light levels of nutrients than if you only give plain, pH’ed water at first.
  • Always check the pHfrom the beginning of your plant’s life to end the of your plant’s life

5.) Install Rapid Rooter and water the seedlings until roots reach the water reservoir – Turn on light to keep seedlings warm for best results!

Make sure to always keep the Rapid Rooter moist but not soaking wet.

If you have a top-feed, place the tube near the bottom of the net pot so the water isn’t soaking the seedling’s roots. You just want water dripping out the bottom so the root can use it for oxygen and water until it’s fully established in the reservoir.

Add your Rapid Rooter(s), and fill around the edges with extra clay pellets to hold each one in place.

Since your seed has already sprouted and been in placed into the right growing position, it’ll often pop its head out within just 12-24 hours! Sometimes you see just the leaves, but occasionally you actually see the seedling push the shell above ground. I keep the grow light on even before the seedling appears. It helps keep it warm and guide it toward the light.

When this happens the shell usually falls off on its own as the seedling grows!

The Rapid Rooter in this picture is a little too wet, which makes the seedling prone to “damping off.” If you ever notice the Rapid Rooter actually looks wet or shiny, it’s too much water. Try turning the top-feed off every few hours, or hand-watering the seedling at first. Too much moisture can kill!

Don’t use a humidity dome on seedlings unless it’s very dry where you live. If you do use a dome, consider keeping a vent open and watching the humidity. A young seedling doesn’t require high humidity, and they tend to get “wet feet” and stop growing in constantly wet conditions.

Now that your seedling in in the tank, it’s time to learn how to….

6.) Take Care of Hydro Seedlings

Here are tips for taking the best care of hydroponic marijuana seedlings:

  • Leave roots alone as much as you can with young seedlings in a hydroponic setup. It takes them a little while to get all established in the tank, almost like a fish, and during that time seedlings are much more sensitive to their roots being touched or being moved around. If at all possible, try to let the seedling grow in the same place without being moved for at least a few weeks until you put them in their final home, or even just start them in their final home!
  • Avo >These seedlings are a few weeks old, and the grower plans to move them all to the

This is a time-lapse video of a cannabis seedling sprouting and growing over 13 days.

Cannabis seedlings just getting their bearings – try to avoid moving or disturbing them until they are growing fast, with new leaves every day!

Big cannabis plants ready to switch to the flowering stage

I thought hydro plants liked it cold?

Just like in soil, cannabis plants in hydro tend to grow faster in relatively warm temperatures. This is a somewhat controversial statement because a lot of hydro growers prefer to keep their temperature lower in the grow space to help prevent root rot. In fact, there are some growers right now who are reading this and shaking their heads at me.

There’s good reason to believe that hydro plants would grow better with a cool reservoir. For example, the bad microorganisms that make root rot don’t survive well at lower temperatures. Additionally, water can physically hold more oxygen at lower temperatures, which seems like it would be great for faster plant growth. Because of this, lots of growers will AC their room to 60°F, and/or get a water chiller to cool their water reservoir to a similar temperature.

I do agree that if the temperature is above 80°F, your plant is a lot more likely to get root rot. However, I personally have not found that cool temperatures are adequate to prevent root rot. Even if the temperature is 60°F, you still need lots of bubbles and a “good bacteria” supplement like Hydroguard to prevent root rot in many cases.

I’ve seen several growers buy a water chiller and still get root rot. So I personally don’t believe cold temperatures are the best way to go to keep roots healthy.

The other reason I recommend to keep it warmer is because the plants just grow faster around 75°F in hydro. If your roots go from 60°F to 75°F, you’ll see the plants start growing faster in just a day or two, just like how plants in soil grow faster when it’s warm!

Just like in soil or coco, cannabis plants in hydro grow fastest when it’s a little warm, around 75°F!

Although there may be more oxygen dissolved in the water at lower temperatures, at least in my grow tent that apparently isn’t the limiting factor to growth, because plant growth speeds up at warmer temperatures.

I’ve found that if the grow space feels cool to you, it also feels cool to your plant most likely, and it may not be growing to its full potential. Some Sativa strains are particularly sensitive to the cold, though some Indica strains from cold climates will still thrive at lower temps.
Autopsy: Why Aren’t My Seeds Sprouting?

If your seeds still aren’t sprouting and growing properly, consider the following factors.

If there’s no germination at all…

  • Temperature may be too hot or cold – aim for 75-80°F
  • Too wet – seeds and seedling roots should always be moist, but should not stay wet
  • Too dry – if a root dries out the seedling can die!
  • Bad seeds – It might not be you, it could be the seeds themselves! How can I tell if seeds are viable?

If seeds sprout, but then stop growing…

  • Temperature is too hot or cold – aim for 73-78°F
  • Too wet – even though your plants are growing with root directly in water, new seedlings don’t like “wet feet”. They don’t like for it to be too wet near the seed for too long, so make sure your Rap >Unfortunately sometimes you will never know why certain seeds just don’t thrive! It’s all part of nature ?

Watch your temperatures- Ideally the water flowing through your system will be about 65 F (18 C) to facilitate good nutrient absorption and to prevent the buildup of algae. The air temperature, however can be warmer. If you can achieve about 75 F (24 C) in your grow room, your marijuana plants should be quite content.

10 Key Tips for Growing Marijuana Using Hydroponics

Takeaway: Getting started using hydroponics to grow marijuana can be tricky. Here are ten tips to make it a little bit easier.

The cliché, “an ounce of prevention equals a pound of cure” may well be overused, but it is still a good measure to use when growing marijuana. If enough attention to detail is taken during the setup phase of a hydroponic grow operation, then the chances for a successful crop are greatly increased.

The precise course of action taken will depend on your unique space and resources, and of course any unique needs of the particular strain of cannabis that you are growing. All that aside, there are still some tasks and practices that should be observed in any hydroponic growing area to keep your plants as healthy and productive as possible.

    Start with sterile tanks and equipment- If you can afford to buy all new equipment to start your growing operations, this step may not be necessary at first, but eventually all tanks, reservoirs, pipes, filters and any other physical part of your hydro system will need to be sanitized to prevent the development and spread of pathogens, especially root rots. Plan on having several bottles of isopropyl alcohol and hydrogen peroxide on hand to disinfect your equipment on a regular basis.

Make sure you start with clean, pH neutral water- Ideally the water circulating through your hydroponic system is at a pH of 7. If not, a reverse osmosis (RO) system will create and provide neutral water. Distilled water can be used as well until an RO system can be obtained.

Watch your temperatures- Ideally the water flowing through your system will be about 65 F (18 C) to facilitate good nutrient absorption and to prevent the buildup of algae. The air temperature, however can be warmer. If you can achieve about 75 F (24 C) in your grow room, your marijuana plants should be quite content.

Maintain proper humidity levels- Cannabis plants do best in varying levels of humidity based on their stage of development. When your “girls” are young, they need to have humidity levels in the 60-70 percent range. As they develop and move into the blooming phase, they only need about 40 percent humidity. This can be best achieved with a humidifier and dehumidifier used accordingly.

Attain proper lighting- There are numerous types of grow lights out there and champions and critics of all. The right types of grow light for your setup will depend on your space, the distance between your lights and your plants and your budget. High Intensity Discharge (HID) lights are better for larger grow rooms with good airflow and ventilation. Compact Fluorescent lights (CFL) are better for smaller rooms. Light from Light Emitting Diode (LED) fixtures is good for small grow areas, but is more costly than the CFLs. Whichever type is selected, make sure that it can produce light in sufficient amounts between 400 and 700 nanometers. A relatively inexpensive light meter can help to determine if your grow lights are getting the job done.

Maintain proper ventilation/air flow- Keeping the air moving around is critical for plant health and aids in even temperature distribution. Fans should be mounted or placed so that they can cover the most area unobstructed. Proper ventilation will help to maintain appropriate air temperatures if it gets too hot, but will also help with air exchange.

Understand pH- Fortunately this is not difficult and there are meters that can take pH readings. This is important because if the pH of your water is not in the proper range, your plants will not grow well or may even die. For hydroponic cannabis, aim for a pH of about 6.0, but allow for a range between high 5s and low 6s.

Understand EC readings- Electrical conductivity (EC) is a measure of the total dissolved solids (TDS) in your hydroponic water. Like with pH, there are many effective meters on the market and there are many that take both readings (pH and EC). The EC level will tell you how rich in nutrients your circulating water is. If the EC is too low, your plants aren’t getting enough; if it’s too high, you can “burn” your plants with too high of a nutrient level. The EC for hydroponically grown cannabis will fluctuate depending on the stage of growth. As seedlings or clones are first put into a system, the EC levels should be less than 1.3 and can be as low as .5 for clones. When they start to grow however, expect to maintain an EC level that continually climbs toward 2.0. When your plants finally reach the flowering phase, they may need an EC up to almost 2.5 depending on the strain grown. Check your EC levels often. The closer you can maintain proper EC, the more productive your cannabis plants will be.

Find a reliable seed source- All of the planning, preparation and procuring of necessary products can’t make cannabis of poor genetics into a robust strain. A cannabis plant can only produce what it is genetically predisposed to produce. Improving its growing environment and attending to its needs ensures that it will come as close to this potential as possible.

  • Keep good records – You cannot improve what you cannot measure. Even the best growers have bad crops and sometimes novices get lucky. To remove as much of the “luck” factor and to focus on results, keep track of everything. The more detailed notes you keep on temperatures, planting dates, EC levels, pH levels, humidity levels and any other factor that you can measure, will allow you to make informed decisions going forward to make continual improvements or to maintain high yields.
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