Best Ph For Cannabis Seed Germination

Want healthy, productive plants? Dial in your potential hydrogen and you’ll be on your way to a thriving crop. Struggling to wrap your head around pH? Click here for an in-depth overview of how pH affects your cannabis plants, whether grown in soil or hydro. 1. Germinate hemp seeds directly into soil 2. Activate cannabis seeds with water 3. Germinate cannabis seeds with paper towels – GIF

What are the Best pH Levels for Growing Cannabis?

Want healthy, productive plants? Dial in your potential hydrogen and you’ll be on your way to a thriving crop. We discuss the importance of achieving the right pH balance with a seasoned growing pro.

The pH and nutrient concentration of a cannabis plant’s medium is a lot like a transistor radio; you have to dial in the right numbers to unlock its full potential.

Whether you are growing with a soil or soilless setup, pH (potential hydrogen) measures the acidity and alkalinity of the medium, which in turn controls the nutrients the plant can absorb.

Students enrolled in the Cannabis Professional Series at Kwantlen Polytechnic University, based in Surrey, British Columbia, learn about the importance of ideal pH levels early in the course.

“It’s something that’s misunderstood, often overlooked, and it’s highly important,” says Nico Hach é , one of the program’s instructors and a horticultural consultant with Root to Shoot Solutions. “People talk about nutrient lockout, that’s generally pH related.”

Soil pH meter – Rukawajung/Shutterstock

Cannabis plants prefer a slightly acidic environment for its roots. Growers using soil as their medium should adjust their pH to a range of 6 to 6.8. For a soilless garden, pH should sit between 5.5 to 6.5.

Allowing a pH range, regardless of the medium, ensures the plant is able to absorb the variety of nutrients required for optimum growth. For example, the plant’s ability to absorb manganese increases with a more acidic medium. Numerous pH and nutrient uptake charts are available online to illustrate the ideal pH for each element needed throughout the vegetative and flowering stages of growth.

“A range allows marijuana to absorb what it likes,” says Hach é. “Your pH doesn’t change your concentration of nutrition, it changes the availability of nutrients. Even though the nutrients are there, they might not be up-taken, or they may be absorbed in excess.”

Young cannabis sativa plant in its first weeks of growing. Yellow leaves could be a sign of chlorosis or unbalanced water pH. – Moha El-Jaw/Shutterstock

While many nutrient companies add pH stabilizers to their products, Hach é recommends frequent water testing to ensure pH remains in the ideal range.

“Water is a big factor that can affect your pH. City water, pond water, or river water, whatever set-up you have, every water source is different,” he says.

Whether or not different cannabis strains thrive under distinctive pH levels is an area that has undergone little scientific scrutiny. Hach é doubts that exploring specific acidity levels based on cannabis species would produce noticeable improvements in yield or quality.

“When you’re talking about changing your acidity like that, it’s complex. Often, they’re hybrid plants, so they’re not true indicas or sativas,” he adds. “It becomes difficult to start playing with that too much.”

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However, matching pH to the plant’s natural environment could help promote native characteristics, like terpene profiles.

“When you think of the regions of the world where these plants come from, they’re complete opposites. All the factors would be different,” Hach é says. “Y ou can treat them exactly the same, they’re both marijuana plants, but you could probably be a little more efficient by fine-tuning indicas or sativas.”

Unlike pH, nutrient concentration should be adjusted for different strains of cannabis. The electroconductivity (EC) or total dissolved solids (TDS) are both measurements used to determine the nutrient concentration in your medium.

“You can definitely manipulate how often and how much you feed individual strains,” Hach é said. “The fast-growing plants will be very hungry. You can afford to feed them more and keep pushing them. If you were to do the same to a shorter, slower growing plant, you might push them too much.”

Cannabis plant with tips of the leaves burned by overnutrition. – Moha El-Jaw/Shutterstock

Overfeeding a plant will likely result in nutrient burn, causing the plant’s leaf tips to turn yellow or brown. Left unchecked, nutrient burn will hinder growth and yield. Underfeeding will also affect the plant’s ability to reach its full potential.

To find out what’s right for the strains in your garden, Hach é recommends starting with a low nutrient concentration in the cloning or seed phase of growth. The EC should gradually increase as the plant matures.

“To find out how far you can go, push. It is a matter of trial and error and knowing your plants. Make sure you take notes and keep track,” he said. “There’s also early telltale signs you can see if you’re pushing too much.”

The EC should peak about halfway through the flowering stage of growth.

“With a nine-week flowering or 10-week flowering plant, I would peak around the fourth or fifth week and then begin to tone it down, so you can start your flush at the end. You slowly creep up,” says Hach é.

A gradual increase, as well as a slow decline, in EC will allow you to determine how far you are able to push your plants while avoiding possible shock caused by drastic swings in nutrient concentration.

“Never have big shifts. A change is a stressor,” says Hach é. “C onsistency is key with anything you do with plants.”

Understanding pH and How It Affects Cannabis Plants

In the world of cannabis growing, pH affects and is affected by everything. Indeed, the entire process of growing plants is a study in the physical dance of pH balance. Read on for an in-depth overview of pH as it relates to growing quality cannabis.

Cannabis cultivation, cannabis history, cannabis culture

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Biochemistry – Genetics – Molecular Biology – Microbiology

While it can be a daunting topic to try and wrap your head around, understanding soil pH is key to growing healthy cannabis plants. In this article, we’ll outline all you need to know about soil pH and how to get it right when growing weed.


  1. What is soil pH?
  2. Why is pH important when growing cannabis?
    1. The benefits of maintaining the perfect pH
    2. The problem with pH imbalances
    3. Understanding and preventing nutrient lockout
    1. Soil pH range: 6.0–7.0
    2. Go organic and forget about measuring pH
    3. Hydroponics and soilless pH range: 5.5–6.5
    1. Cannabis pH — faqs
    1. Using pH down
    2. Using pH up
    3. Alternative ways to lower or raise pH when growing cannabis

    What Is Soil pH?

    pH is a measure of how acidic or alkaline something is. The pH scale ranges from 1–14, with a pH of 7 being neutral (the pH of pure water). If pH is lower than 7, a substance is considered acidic (think vinegar or lemon juice). If the pH is higher than 7, the substance is alkaline, as is the case with soaps, bleach, and ammonia.

    In more scientific terms, pH level has to do with the concentration of hydrogen ions, say in the water you give to your plants. The pH scale is logarithmic to the base 10, which means that water with a pH of 6 is already 10x more acidic than water with a pH of 7.

    Below is a basic chart of the different pH levels of common items:

    1.0 – Battery acid
    2.0 – Lemon juice and vinegar
    3.0 – Orange juice and soda
    4.0 – Tomato juice
    5.0 – Black coffee and bananas
    6.0 – Urine and milk
    7.0 – Pure water, not tap or bottled water
    (the pH running or bottled water can vary considerably)
    8.0 – Seawater and eggs
    9.0 – Baking soda
    10.0 – Milk of Magnesia and the water of the Great Salt Lake, Utah

    Why Is pH Important When Growing Cannabis?

    So, you now know what pH is. But how exactly does the pH of your growing medium affect the growth and health of your plants?

    As you already know, all plants require nutrients for healthy growth. They require the macronutrients nitrogen, phosphorus, and potassium, as well as micronutrients and minerals including calcium, magnesium, iron, copper, and a whole lot more. If plants cannot access these nutrients, it will lead to deficiencies and other serious health problems.

    The issue with cannabis plants is that they are only able to take up nutrients within a small pH window, which ranges from about 6–7 when growing in soil. If the pH is lower or higher than that, the plant cannot take in nutrients, even if they are present—thus spurring nutrient deficiencies via “nutrient lockout”.

    In those places where cannabis thrives in the wild, the soil is normally slightly acidic; therefore, homegrown cannabis plants also prefer a slightly acidic environment. However, the way that you grow cannabis also plays a role in the optimal pH level for your plants. Cannabis grown hydroponically or without soil needs an even lower pH than a soil grow.

    The Benefits of Maintaining the Perfect pH

    The benefits of caring for and maintaining your plants’ pH is pretty straightforward; you’ll have healthier plants that demonstrate more vigorous growth and, as a result, produce better harvests. Plus, you’ll also ensure that the time and money you’ve spent fertilising your plants is paying off.

    By regularly checking the pH of your growing medium, you’ll be able to ensure that your plants are able to take up all the nutrients you’re giving them. You’ll also be able to catch any pH imbalances early, minimising your risk of running into nutrient deficiencies later on in your grow (more on that below).

    The Problem With pH Imbalances

    pH imbalances are one of the most common causes of nutrient deficiencies in cannabis plants. As we mentioned earlier, cannabis plants can only take up certain nutrients within a small pH window. If the pH of your medium shifts below or above that ideal window, your plants won’t be able to take up the nutrients in their fertilisers and will start to show signs of a nutrient deficiency.

    Understanding and Preventing Nutrient Lockout

    Nutrient lockout (sometimes referred to as “nutrient lock”) occurs when your cannabis plants can’t absorb nutrients from the soil or the fertilisers you’re using to feed them. One of the primary causes of nutrient lockout is pH imbalance, but it can also be caused by salt buildup near the root zone as a result of feeding with mineral fertilisers (which tend to have a high salt content).

    The Best pH for Growing Cannabis

    We’ve alluded to it already, but the best pH for growing cannabis resides within a narrow window. But, within that window, is there an optimal reading you should try to achieve? And, does that reading change depending on how you choose to grow? Let’s explore further.

    Soil pH range: 6.0–7.0

    If you grow in soil, the optimal pH level for the root zone is between 6.0 and 7.0. However, there is no set number within this range that is “best”. Instead, it can be good to allow for some natural fluctuation within this window to support optimal nutrient uptake.

    So, as you adjust, try a slightly different reading each time. You can, for example, adjust your pH to 6.2 for one watering, then 6.6 the next. As long as it stays within 6.0–7.0, you should be fine. Soil is also more forgiving when it comes to pH imbalances, but it can only give so much.

    If you grow purely organically—where you do not administer mineral nutrients—pH is less of an issue. If you’re using amended or composted soil with organic matter, the microorganisms within will make the nutrients more available to the roots. However, most growers using standard potting mixes and mineral nutrients will indeed have to reckon with pH.

    Go Organic and Forget About Measuring pH

    At RQS, we’re big proponents of organic cannabis growing; not only because it delivers a far superior product, but because it takes some of the hassle out of growing, especially when it comes to pH.

    While using chemical nutrients might seem simple, it can actually take some time and practice to get the hang of properly fertilising your cannabis plants with liquid mineral fertilisers. Organic nutrients, on the other hand, naturally promote the health of your plants by supporting the development of healthy microbial life within your medium.

    Using natural fertilisers like compost, worm castings, and bone meal creates a breeding ground for healthy bacteria and fungi that keep the conditions of your soil optimal, so there’s usually no need to monitor the pH of your soil as closely as you would otherwise.

    Hydroponics and Soilless pH range: 5.5–6.5

    Hydro and soilless grows are a different beast when it comes to pH. If you grow soilless, say in coco, the optimal pH level at the root zone should be somewhat lower than in soil, between 5.5–6.5. The same goes for all methods of hydro.

    With these methods, it is just as important that you allow the pH level to fluctuate across the acceptable range to support nutrient uptake. For example, in hydro, calcium and magnesium are mostly absorbed at pH levels above 6, while other nutrients like manganese prefer a slightly lower pH.

    Then again, this shouldn’t be an issue since pH levels will naturally fluctuate slightly with each feeding in a hydroponic setup. You will only need to correct if the pH level exits the optimal 5.5–6.5 range.

    When growing in coco, perlite, or hydroponically, you are in charge of administering nutrients directly to the root zone via the water, which means huge pH fluctuations are more of a risk than in soil. The inert media used in hydro and soilless grows merely retains water and provides support for the roots. So, when administering nutrients, be careful that you don’t overload your plants.

    How to Test Cannabis Soil pH

    Managing pH level means testing the water or nutrient solution and adjusting it accordingly. This may sound complicated, but it really isn’t.

    To test pH, you can use a digital pH meter or a pH measurement kit with drops. Opinions here differ as to which method is “best”. Some prefer digital pH meters because they are accurate and easy to read, while others like the drops as they are super simple and don’t require calibration. Try them both and see which you prefer.

    Cannabis pH — FAQs

    Let’s break down some of the most common questions related to cannabis pH. Feel free to refer to these if you encounter any pH-related issues during your grow.

    Questions & Answers: Ph

    Do I Test the pH of My Fertiliser Before or After Adding My Nutrients? Always measure the pH after you add any nutrients or amendments as they will change the pH value of your water. After you mix your nutrient solution, use a pH meter or drops to test its pH level.

    If you are growing hydroponically, test a sample from your water reservoir a few minutes after you add your nutrients. Do I Need to Measure the pH of My Runoff After Feeding My Plants? Yes. Always remember to test the pH of your nutrient runoff as this will give you an idea of the pH of your medium. How Exact Do I Need to Get My pH Levels When Growing Cannabis? Don’t get flustered if your nutrients are slightly below or above the optimal conditions we mentioned above. Only react to big changes in pH that may inhibit your plant’s ability to uptake nutrients.

    Measuring pH With Drops

    pH measuring kits usually contain a test tube, a bottle of testing solution, and a colour-coded pH chart. Testing the pH of your soil with these kits is super simple:

    1. Prepare your fertiliser as per usual and stir it gently. Be careful not to over oxygenate your fertiliser as this may throw off your pH reading.
    2. Half-fill your test tube with your fertiliser and add 3 drops of testing liquid into it.
    3. Gently shake the test tube to mix the pH testing solution with your fertiliser.
    4. Use the colour chart to read the pH of your fertiliser and, if needed, use pH up/down products to adjust it.
    5. Repeat this process with the runoff from your fertiliser. If the pH reading from your runoff is far below or above that of your fertiliser and in the danger zone (below 5 or above 7), you may need to regulate the pH of your soil.

    Measuring pH With a Digital pH Meter

    Measuring pH with a digital pH meter (like our pH tester) couldn’t be any more simple. After you’ve calibrated your device, simply stick it into your fertiliser, runoff, and soil to get an accurate reading of the pH in your garden.

    The best way to germinate cannabis seeds!

    With this guide, we would like to explain to you, how to germinate a cannabis seed most successfully. There are three common methods of cannabis seeds to germinate. Properly executed, they will be successful in almost every case.

    1. Germinate hemp seeds directly in soil
    2. Activate cannabis seeds with water
    3. Germinate cannabis seeds in damp cloths

    So that cannabis seeds can be germinated under optimal conditions, in all three breeding types, some basic rules have to be considered. Before we describe the methods exactly, we first want to talk about these basics; The first golden rule is for example, not to treat cannabis seeds with bare hands to avoid the chance of contamination with bacteria or fungus. We strongly recommend the use of clean gloves and some disinfected tweezers!

    Germinate weed seeds – The quality of the water:

    The water temperature should be around 20 degrees and have good quality. The quality of the water can be tested with a PH meter and an EC meter. Recommendation: Osmosis water or drinking water very debil (with little salts and mineral arm).

    The ideal substrate to germinate weed seeds:

    You can work with different substrates. The most common are earth (light mix), coco and rock wool. Even with the substrates, the soil and ambient temperature should be right. A light mix is specially adapted to sensitive plants such as hemp. Most mixtures contain nutrients and minerals for a few weeks, which the young plant absorbs when it needs them.

    For Coco substrate, before working with it, you should test the EC content, as most Coco substrates have a very high value. To lower the value, wash the Coco once with mineral water (osmosis water).

    Breeding for coco and rock wool is also referred to as hydroponic cultivation, which means that significantly more air circulation at the roots is created. But the nutrients that are then fed to his plants are more directly absorbed by them. The risk of over or under-fertilization is greater but also the expected yield. Breeding on hydroponics is what gardeners with more experience.

    Required air, light, and temperature for germination:

    In order not to endanger the germination capacity of the seed, it should be stored in a dark and cool place (6 ° – 10°).

    Before the seed is germinated, it must not be exposed to light and the air temperature should not be below 20° C (68° F) nor exceed 30° C (86° F). Maintaining a temperature around 25°C (77° F) is ideal. For outdoor cultivation, it’s recommended to germinate indoors, letting the seedlings grow for a few weeks, and don’t set plants outside too early.

    Method 1. – Germinate hemp seeds in soil

    1. Prepare material (fill small flowerpots with soil).
    2. Lightly moisten the potting soil with good water. (Too much moisture = mold and fungal danger).
    3. Place the seeds in a 0.5cm recess in the center of the pot. Make sure that the seed is transverse and not upright, this can affect the germination rate. Nature has not shaped the seed without reason oval. If you set the seed transverse, it will easily position itself properly in the soil after germination! When you work with jiffies it works something similar. The jiffy is only soaked in water until it swells apart, then the water is expressed again without crushing it until residual moisture is over. At Jiffy, the factory usually prepares a slight depression for the seed.
    4. Lightly cover the seed with soil so that no light can shine directly on the seed. Also with the jiffi one covers the seeds with a little material. Wet but not wet! Now pour no more that could flush the seed back up and the amount of water is also difficult to control.
    5. In case of too little moisture, we recommend wetting the plant with a spray bottle.
    6. Now put the plant in a safe place and depending on the variety and genetics can be expected in the next 36 to 72 hours with a first result. In some cases, it can take up to 6 days.

    Method 2. Germinate cannabis seeds in a paper towel.

    1. For preparation, we gonna need two plates, some sheets of kitchen roll, good quality water as described above, and our seeds.
    2. Put two sheets of kitchen paper on one of the plates and moisten them with water.
    3. Put your seeds on the damp cloth and put two more kitchen towels over it.
    4. Moisten also the upper cloths. Runoff excess water that the wipes are only slightly saturated.
    5. Put the second plate on the other plate like a shell.
    6. Store in a dark place and check daily that do not dry out the kitchen towels and of course to see if the seedlings are already broken. Once it is germinated, a small white shoot comes from one side. Now the time has come, the seed can be placed in the substrate of your choice. Carefully remove the seeds with tweezers from the cloths and carefully place them diagonally with the small germ downwards into a prepared hole. Only so deep that the seed is slightly covered with soil (max 5mm).

    7. Wait, wait, wait and then be happy.

    Method 3. Germinate cannabis seeds in a cup of water

    This method is particularly suitable for activating seeds that have been stored for a long time

    The addition of hydrogen peroxide is suitable for softening the husk of the hemp seed. About 3 – 5 drops per 100 ml of water are sufficient.

    • Prepare a cup of water at a temperature of about 12 degrees Celsius (54 degrees Fahrenheit).
    • Put the seeds into the water for 12 hours.
    • Prepare to plant the seed in a small flower pot. Exactly as we described in method 1, under point 3.
    • After planting, cover the seed with the substrate and moisten again with water.
    • After about 2 – 3 days, the germ should gradually see daylight.

    Cannabis seeds do not germinate? These are the most common mistakes:

    1. The pH of the water is too high or too low. Regardless of the method used to germinate the cannabis seeds, the pH should always be between 5.5 and 6.5.
    2. The EC value of the water is too high, it should be below 0.8.
    3. The water temperature was ignored, it should be between 20 ° and 22 ° celsius.
    4. If you let the hemp seeds germinate into soil, it may be that too much water was used, the soil was fertilized too much, or that the seed was pushed too deep into the soil, or was placed upside down.
    5. The seeds were exposed to strong temperature differences during transport.

    This information is only of interest to customers who live in a country where cultivating and cultivating cannabis seeds is not a violation of the law.

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