Optimizing Hydroponic Nutrient Water for Maximum Cannabis Growth

We’ve posted hundreds of articles on growing hydroponic cannabis plants, and as you shuffle through them, you’re bound to come across the term nutrient water. This is the water that gives life and energy to your cannabis plant. But there’s a lot of nuance to this. It's pretty simple to grow some of the best hydroponic cannabis, but you just need to understand the basics of it all. 

It’s not just magical water that flourishes your plant or regular tap water with everything your plant ever needs. Instead, it’s a carefully mixed solution that contains all the nutrients your plant needs without any contaminants that it doesn’t need. 

But it can still be a bit confusing when it comes to nutrient water. Don’t worry, though; we’ve got your back. In this article, we will go over everything you need to know about nutrient water. From tips about making and using it to the pH and EC, we will focus on things you need to do when growing cannabis hydroponically. 

An Overview of Hydroponic Cannabis Cultivation

Growing cannabis in hydroponic setups is popular among growers as it offers more control over the plants. Unlike soil, hydroponics involves cultivating plants in nutrient water while managing crucial elements like pH so the roots can absorb the nutrients effectively.

Hydroponics provides growers with a way to grow plants without the constraints of soil-based techniques, maximizing plant growth potential. This is not to say that growing in soil is bad; however, hydroponics offers more control and allows you to tailor everything according to your plant’s needs in a precise manner. 

In hydroponics, plants are cultivated in growing mediums such like coco peat, perlite, rockwool, etc., with their roots either submerged directly or exposed periodically to nutrient-rich water solutions. You will be able to reduce the likelihood of pests, diseases, and nutrient imbalances as you can fine-tune everything based on your plant’s needs. 

There are various hydroponic systems such as like deep water culture (DWC), nutrient film technique (NFT), aeroponics, and drip systems. Each system offers different benefits in terms of delivery methods, oxygenation levels, and root zone management.

But, no matter what system you use, the main idea remains the same — creating perfect growing conditions for cannabis plants to thrive and produce high-quality buds. 

Significance of Nutrient Water

If you choose to use hydroponic systems to grow marijuana, the nutrient water is vital as it gives plants everything they need to grow healthy. These nutrients are classified into macro and micronutrients like nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, and other trace minerals. It's crucial to balance these nutrients in the water solution to support processes such as photosynthesis, root growth, formation of buds, and overall development. 

The nutrient water also helps to maintain the pH level of the growing medium to ensure proper nutrient absorption by the plant roots. Keeping the pH within the range of 5.5 to 6.5 (6 to 7 for soil) is crucial to prevent nutrient deficiencies or toxicities that can impede plant growth and reduce yield.

For hydroponics, the nutrient water serves as the foundation of cannabis cultivation. If you get this right, everything else will fall into place. By understanding the basics of nutrients, you will be able to grow better plants and get more yields at the end of it all. 

Understanding Nutrient Needs of Cannabis Plants

Whether you grow your plants in soil or hydroponics, it will serve you well to understand more about the specific nutrients required by the plant at different growth stages. Like all plants, cannabis relies on a balanced supply of macro and micronutrients to support its functions and promote healthy growth. 

Key Macronutrients for Cannabis Growth

Nitrogen (N)

Nitrogen is a macronutrient that plays the main role in supporting plants during the vegetative phase. It is crucial for chlorophyll production, which is responsible for capturing light (whether it’s sunlight or grow light) during photosynthesis, and then helps to convert the light into carbohydrates that help the plant develop lush green leaves. This is also why you typically use more nitrogen (N) in the NPK ratio during the vegetative phase. A strong supply of nitrogen promotes strong stems and leaves, setting the stage for productive cannabis plants.

Phosphorus (P)

Phosphorus is another macronutrient that regulates many processes in growing cannabis plants as it influences everything from roots to flowers. Not only does it help with energy transfer at the root level for efficient nutrient absorption but it also aids the plant to develop stronger root systems and buds. Typically, you’d use more phosphorus during the pre-flowering stage, right before the plants start producing flowers. 

Potassium (K)

Potassium plays a major role in regulating the water balance by controlling water absorption and transportation within the plants. This nutrient is especially important to enhance the plant’s ability to withstand extreme conditions. It also helps the plants maintain optimal cellular performance by supporting their robust growth and development at every stage of the cultivation process.

Calcium 

Calcium helps plants strengthen their cell walls. It also lends support as a signaling messenger that regulates enzyme functions. From cell division to signaling, calcium is crucial for plants to develop properly. Without this nutrient, the leaves get distorted and you’ll also notice general stunted growth. 

Magnesium

Magnesium is a crucial component in the production of chlorophyll without which the plants can’t survive. It helps the plants harness energy through light and also enhances the plant’s metabolism. Calcium and magnesium work in tandem to strengthen the plant’s cellular structure, so they are both important for overall development. 

Sulfur

Although plants don’t need sulfur in large quantities like nitrogen or potassium, it is still very important for the growth and health of cannabis plants. It is involved in the production of biomolecules for plant development. From playing a major role in plant metabolism to helping with enzyme activation and nutrient absorption, plants simply cannot do without sulfur. Moreover sulfur helps in creating metabolites like vitamins and phytochemicals that increase the plant's ability to withstand challenges and boost their defense mechanisms.

Importance of Micronutrients

As the name suggests, micronutrients aren’t needed in large amounts like macronutrients, but do not underestimate their importance as they are just as vital for the development of cannabis plants. These trace elements help the plants produce important hormones and also protect them against oxidative stress by enhancing their defense mechanisms. In short, they make the plants resilient to stress. 

Here’s a quick overview of some of the most common micronutrients that help in the cultivation of cannabis plants:

Iron 

Iron plays a big role as a micronutrient essential for chlorophyll production. It also helps in converting carbon dioxide and water into glucose and oxygen. By maintaining various processes, iron supports strong growth, lush foliage, and optimal yields in hydroponic cannabis farming.

Zinc, Copper, Manganese, and Boron 

These micronutrients play roles as cofactors that contribute to enzymatic reactions and metabolic pathways within cannabis plants. Zinc, for example, supports enzymes involved in managing carbohydrates and hormones. Copper helps with photosynthesis and respiration. 

Manganese, on the other hand, helps in producing chlorophyll and safeguarding plant cells from damage. Although boron is required in minute quantities, it is vital for forming cell walls, developing pollen, and setting fruit to enhance plant fertility and reproduction. Together, zinc, copper, manganese, and boron contribute to the growth and resilience of cannabis plants by facilitating these essential biochemical processes.

Molybdenum and Chlorine 

Chlorine and molybdenum complete the group of micronutrients with roles in cannabis physiology and metabolism. Molybdenum aids in converting nitrates into ammonia for synthesizing amino acids.

Chlorine is often underestimated, but it helps with photosynthesis to a big extent. It helps maintain the balance in plant cells ensuring water absorption and turgor pressure while also boosting disease resistance by strengthening cell walls and activating defense mechanisms. 

Tips to Make the Best Nutrient For Hydroponic Cannabis

Now that we have the basics sorted, here are a few tips you should keep in mind when it comes to your nutrient water. 

1. Choose The Right Setup

Even before you dive into water management and nutrient water for your cannabis plant, you need to first pick the right type of hydroponic system for your cannabis plant. You’ll find many types of hydroponic systems out there, like nutrient film technique, aquaponics, or deep water culture. 

Whichever one you choose will determine how you manage your nutrient water. Here are some of the things that come into play here.

• Reservoir Size 

Not many growers pay attention to this aspect; they pick any bucket they can find to use as a reservoir, but you don’t have to make the same mistake. The size of your reservoir matters a lot more than you’d give it credit for. 

For instance, if you have a small reservoir, you must frequently monitor and adjust the nutrient water. On the other hand, a large reservoir will give you more buffer against sudden nutrient fluctuations in the water, which means it’s more stable. So, make sure your reservoir is adequately sized for your cannabis plant. 

Also, choose a dark opaque reservoir that doesn’t allow light to pass through. Otherwise, you’ll be fighting algae all the time as they have the perfect environment to grow and thrive. Algae can block your equipment and prevent the cannabis plants from growing properly so it’s important to get an opaque reservoir with a lid to prevent such issues. 

• Water Quality 

The next thing that comes into play is the quality of water you use. Your plant needs nutrients to survive, and sometimes, these nutrients may already be present in the water (like tap water). 

On the contrary, some types of water may be so contaminated, that it will nullify the nutrients you add to it. Not that it will destroy the nutrients, but the contaminants may make it difficult for the roots to absorb the nutrients, or worse, lead to nasty disorders for your plants. 

So, you must regularly test your water and ensure it is free of contaminants and has the right pH range. More on pH later. Ideally, you should use filtered water, and if you are adamant about nutrients, you can even use RO water. 

• Nutrient Concentration 

When you add nutrients to the water, you need to make sure you are adding the right nutrients as per your hydroponic system. For instance, if your system exposes roots to the water more frequently, you must be more conservative with the nutrients. 

Similarly, if you are using aquaponics with fish in the reservoir, you don’t need to add any nutrients at all (in most cases). The fish will take care of that. You should also factor in things like the temperature, humidity, growth stage, etc. of your growing room. 

• Hydration Schedule 

Similarly, you need to pay close attention to the hydration schedule based on your hydroponic setup. This is vital; mistakes here can lead to nutrient lockout, toxicity, or deficiencies. You never want to under or over-water your cannabis plant. 

2. Pick Good Hydroponic Nutrients 

Nutrients are one of the pillars of hydroponic systems. Your plant does not have the luxury of nutrient-rich soil, and it relies on you (and the water) for the nutrients. As a grower, you play a role in creating and maintaining a solution that precisely meets the plant's nutritional requirements throughout its growth cycle. Unlike soil, hydroponic setups are comparatively unforgiving and demand a well-balanced supply, so it’s up to you to provide them. 

Essentially, you need to ensure you only use high-quality nutrients that are appropriate for your cannabis plant. They play a vital role in determining the strength, well-being, and yield potential of cannabis plants. 

Every nutrient you choose holds a lot of importance as they are delivered directly to the roots in this soilless environment. The nutrient solution acts as the life force of the system providing plants with crucial elements for growth, metabolism, and ultimately for producing robust and plentiful yields. 

Fortunately, you don’t always have to pay big money for this as long as you pick the right nutrients. But, how do you choose these nutrients? A quick Google search will show you so many options that it gets challenging to distinguish between superior and inferior formulations. However, you can make informed decisions by focusing on just a few key factors:

Signs of Good Hydroponic Nutrients

• Always go for mineral-based nutrients over other options to avoid introducing contaminants and residues that can disrupt nutrient uptake and system functionality. This means that you shouldn’t go for other types of nutrients even if they are advertised as being organic. 

This doesn’t mean that organic nutrients are bad; however, they aren't suitable for hydroponic systems. Some growers prefer organic nutrients. However, you shouldn’t go for organic fertilizers if you’re into hydroponics. Simply switch to growing cannabis in the soil if that’s your main criterion. This is because organic formulations contain worm castings, guano, or blood meal that can build up in the reservoir and pipes causing blockages. Moreover, organic matter breaks down slowly over time, but since hydroponics relies on the immediate delivery of nutrients, it can result in deficiencies. 

• Choose chelated nutrients bound to organic molecules for stability and solubility promoting efficient nutrient uptake across a wide pH range. In essence, the process of chelation helps the plants absorb nutrients more efficiently which ultimately leads to better growth and yields. 
• Don’t chase massive yields. Instead, focus on the nutrients. If you select good-quality nutrients that are compatible with your setup, you will establish a strong foundation for the plants. Ultimately, the yields will come automatically. 
• We have already discussed the importance of macro and micronutrients. So, you should know that your hydroponic nutrients should contain a balanced mix of both types of nutrients tailored to meet the requirements of cannabis plants at different growth phases. Balanced NPK ratios and a wide range of micronutrients promote plant growth and reduce the chances of nutrient deficiencies or imbalances. With this, you will avoid unwanted nutrient deficiencies that may take up your time and also destroy the plant’s health. 

Signs of Poor Nutrients

• Many growers are concerned about the price of these nutrients — and rightly so. Almost everyone operates on a tight budget, so it’s not wrong to consider the price before purchasing the nutrients. However, don’t prioritize the price so much that you compromise on quality as it could harm the plants in the long run. Yes, nutrients made for plants growing in soil are cheaper but that doesn’t mean that you can use them for hydroponics.
• Avoid going for broad-spectrum nutrients even if they are advertised to work with various techniques of cultivation. While they may seem versatile, these formulations may not offer the ratios and chelation needed for optimal nutrient absorption in hydroponic cannabis growing.
• If your nutrient solution appears cloudy after mixing, it might not be entirely soluble in water. This might lead to an inconsistent delivery of nutrients to your plants which could result in deficiencies or toxicities. 

3. It Should Have A Good NPK Ratio

Next, you need to make sure your nutrient water has the right NPK ratio and other nutrients. This is crucial. Let’s dive into it. 

NPK refers to the three macronutrients your cannabis plant needs: nitrogen, phosphorus, and potassium. These should be listed on the nutrient packaging, but more than that, the packaging must also contain the concentration of each and their ratios to one another. 

Your cannabis plant needs these macronutrients in different ratios when it’s growing. For example, your cannabis does not need a lot of nitrogen during bloom; so if you give a lot of nitrogen at that stage, it will suppress flower production, drastically reducing your yield. 

Ideally, you can start with 3:1:1 for the vegetative stage and switch to 1:3:2 for early bloom and 0:3:3 for late bloom. You can check these ratios in the “Grow” and “Bloom” nutrients or “Part A” and “Part B” nutrients when you purchase commercially bottled nutrients. Sometimes, the NPK ratios will differ. But, as long as there’s more nitrogen during the vegetative phase and more potassium during the flowering phase, your plants will be fine. 

Sometimes, the nutrients meant for the vegetative phase will have less nitrogen. A popular brand has 2:1:6 for plants in the growing phase; however, the other nutrients they have supplied will make up for it. Typically, you will mix Part A, Part B, and the micronutrients, so you don’t have to worry about that. Do not try to add extra nitrogen in such cases. Simply follow the recommendations. 

Other than that, your nutrient water should also contain magnesium, calcium, iron, sulfur, and other micro-nutrients like boron, cobalt, copper, manganese, molybdenum, zinc, etc. 

Remember, the nutrients you use for a hydroponic plant aren’t the same as those used for a soil-based cannabis plant. Hydroponic nutrient water needs more micro-nutrients (still in trace quantities) since the roots do not have soil for that. 

This is why hydroponic nutrients contain higher levels of nitrogen and micro-nutrients while having a bit less phosphorus since the latter is already more accessible for plants in a hydroponic setup. In soil, phosphorus is stolen by colloidal particles and microorganisms. 

Additionally, hydroponic nutrients do not use organic nutrients. Soil uses organic nutrients, but they need to be broken down by microbes in the growing medium to be accessible to the plants. Plus, they can clog up your hydroponic system, as mentioned above. 

Instead, hydroponic nutrients are usually formulated with chelated minerals, which undergo various processes to become easily accessible to the plant.

Don’t worry; the lack of organic materials in a hydroponic nutrient solution does not mean it is not eco-friendly. They can still be produced from organic matter, but the breakdown process occurs in a lab and not the growing medium. 

4. Focus on the pH 

One of the most important things about your nutrient water is that you must always keep an eye on the pH of the nutrient solution. It refers to the alkalinity and acidity of the solution. Cannabis is very particular about pH. 

Generally, most hydroponic cannabis strains thrive in a pH range between 5.5 to 6.5, but the sweet spot is at 5.7. Try to maintain this if you want perfection. If not, maintaining it between the range will do just fine. You must invest in a pH pen to measure the pH regularly. 

Like soil, the pH of the nutrient water in a hydroponic system also determines how accessible essential nutrients are to cannabis plants. Most nutrients are readily available within the ideal pH range. Although you’ll notice slight deviations at times, drastic fluctuations can prevent the roots from absorbing nutrients properly, thereby resulting in deficiencies. Or, the plant may absorb too many nutrients leading to toxicities that eventually affect the growth and yield.

In addition, fluctuations in the pH can also disturb the activity of microorganisms in the root area affecting circulation and root health. In acidic environments, these fluctuations can further worsen imbalances in nutrients, especially calcium, magnesium, and phosphorus. In contrast, pH fluctuations in alkaline conditions can lead to shortages of micronutrients like iron, manganese, and zinc. 

In hydroponic systems, pH fluctuations can be devastating for the plant as there’s no buffer like soil to manage issues. This is why you’ll see the plants get affected immediately when growing in hydroponics. 

So, check the pH of your nutrient water every few days. If it starts straying, you should use a pH up/down solution to correct it. Simply add them to the reservoir or nutrient water to increase or decrease the pH so the nutrient water remains in the ideal range for effective nutrient absorption and plant development.

And don’t ignore the problem. If the pH keeps fluctuating regularly, you might be adding something to the water that is affecting the pH over time. 

Next, you should pay attention to the EC or electrical conductivity. The EC measurement determines the amount of dissolved salts in the solution, indicating its strength and composition. EC values tell you about nutrient availability, meaning higher EC values signify a larger concentration of dissolved nutrients.

Like the pH, you should always monitor the EC levels to assess the concentration of nutrients in the solution and ensure that it meets the requirements of cannabis plants at various growth stages.

For instance, the seedlings will perform well with low EC levels and avoid nutrient burn whereas mature plants will require higher EC levels to meet their increased needs. Thus, by monitoring the EC, you’ll be able to prevent nutrient burns and deficiencies and help the plants grow to their maximum potential. 

5. Follow the Manufacturer’s Recommendations 

Lastly, always follow the manufacturer’s recommendations when it comes to making the nutrient solution. You’ll find all kinds of tips on the internet, but no one knows the nutrients you are using better than the minds that developed it. 

If the packaging recommends using a certain level of nutrients, do not go your own way and use twice that. Stick to the recommended dosage and usage. 

In some cases, you may want to take a conservative approach. For example, if you are growing a short strain, you don’t want to give it too much nutrients. In such cases, you can start by using a more diluted solution and dial it up over time while keeping an eye out for nutrient lockout or toxicity. 

Troubleshooting Common Problems in Growing Hydroponic Cannabis

Growing cannabis hydroponically allows for control of the growing environment but it poses its own set of challenges. It's crucial to understand and effectively deal with these issues to ensure your plants stay healthy and yield the results you expect. Let's take a look at some common problems you can encounter in hydroponic setups and ways to resolve them.

Understanding Nutrient Imbalances in Hydroponic Cannabis Growth

In a controlled hydroponic setting, managing nutrients is vital for promoting plant development and maximizing yields. However, maintaining the right balance can be tricky, and lead to deficiencies or excesses. Recognizing the signs of these issues on your plants and addressing them promptly are key to maintaining plant health. 

Nutrient deficiencies exhibit specific symptoms on the leaves. For example, nitrogen deficiency typically shows up as chlorosis or yellowing of leaves starting from the lower leaves and then spreading to the younger ones if you don’t take care of it immediately. While phosphorus deficiency may cause the leaves to turn purple with stunted growth and a delay in flowering, potassium deficiency often leads to the browning and upward curling of leaf edges. 

The plants will show many other signs but you must be able to distinguish between various deficiencies to correct them. Often, these imbalances occur when the pH is not in the right range, so start your diagnosis by taking a good look at the pH. 

Conversely, an abundance of nutrients can also hurt the plant. For instance, excess nitrogen can make the leaves look more green than usual. They also look like they are coated in a thin layer of wax. Eventually, the leaves may look like claws and the buds may not form properly either. 

Excessive phosphorus may cause burning at the tips of leaves, leaf decay, and affect the development of the roots as well. Similarly, excess potassium could lead to necrosis, leaf curling, and reduced nutrient absorption.

As mentioned already, check the pH and EC to determine the problem. If the pH is not in the right range, adjust it and wait for the plant to recover. If the problem persists, there might be a problem with the nutrients you’re using. Take a look at the guide for nutrient deficiencies and figure out whether your plant is suffering from insufficient or excessive nutrients. Make sure you also check the undersides of the leaves for pests lurking there. 

Once you’ve done everything possible and the plant refuses to recover, wait to harvest the plants and clean your reservoir well to ensure there are no blockages that could be preventing the roots from absorbing nutrients properly. You can also switch to another brand of nutrients. 

How to Combine Three-part Nutrients for Growing Cannabis

Mixing three-part nutrients requires blending three elements to create a balanced nutrient solution that meets the specific requirements of your plants. The nutrients and how you mix them can differ from one brand to another. While one company can have just two parts, another can have three. Regardless, most of these brands have macronutrients and micronutrients. Assuming you have a 3-part system, here’s a quick overview of how you mix them:

• Firstly, do not ever mix all your nutrients at one go or you’ll have a big mess on your hands. As the nutrients are concentrated, they will cause a nutrient lockout, and your plant won’t be able to absorb any of them. Instead, add your nutrients one after the other. You can start with the micronutrients unless the manufacturer specifies otherwise. 
• Start with fresh water of your choice and mix in the nutrients. Mix it thoroughly every time you add new nutrients. 
• If you’re using additives containing silicon, you can start with them at first and then add calcium. Any supplements with calcium should also go in after silicon. 
• Next, add your Grow or Bloom Part of the nutrients and mix well. 
• Check the pH and adjust it by adding pH Up or Down to increase or decrease the pH. 
• Wait for at least 20 minutes, recheck the pH, and adjust again if necessary. Make sure to check the EC levels also to confirm that they are staying within the desired range. Pour the solution into your reservoir or irrigation system ensuring that all plants receive a consistent distribution.

Summary: Optimizing Hydroponic Nutrient Water for Maximum Cannabis Growth

Isn’t it simple once you understand the nuance of nutrient solutions for hydroponic cannabis plants? To sum it all up, start with the right hydroponic solution, use a big reservoir filled with clean water, and use the right type of hydroponic nutrient. 

Then, make sure the nutrients you use have the right NPK ratios and enough micronutrients. Additionally, you should also focus on the pH of the solution and follow the manufacturer’s recommendations unless you want to be more conservative and play it safe. 

That’s it. Keep these tips in mind and you’ll be using nutrient water unlike ever before. Your plant will thank you with a plentiful, colorful, and potent yield that even your friends will envy.