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Common nutrient deficiencies in hydroponics

The Nutrient Deficiency Checklist

Both beginner and expert growers have a bad habit of trying to diagnose nutrient deficiency purely from a plant’s appearance. However, as plants can have very similar physical symptoms for different deficiencies, this could lead you to trying to fix the wrong problem – and as a result, making the original problem worse.

There are plenty of potential causes for nutrient deficiency and poor plant health. Which is why we’re sharing this ultimate checklist to help you identify specific problems – so that you can treat them as quickly as possible. 

What is nutrient deficiency?

As we’ve discussed in previous posts, plants need the right balance of nutrients in order to thrive. They need the right amount of macro and micronutrients like nitrogen, calcium, iron and zinc. These nutrients are often provided by the soil you use, as well as additional fertilizers if you choose to use them. 

But even with this natural supply of nutrients, there are still plenty of reasons your plants could begin to suffer from a deficiency. 

Checking for nutrient deficiency

As mentioned above, there’s more to nutrient deficiency than a withered looking plant. There are a huge number of things that could cause a health problem for your crops, so you should check each of the below parameters before trying to diagnose the issue. 

Insects or disease

While nutrient deficiency can make your plants look a little sad, so can pests or disease. Checking your plants for signs of insect damage or infestation could help you identify the root cause to your droopy dracaena. Signs of pests included holes, discoloration or dehydration in the leaves. There may also be bite marks and insect eggs in different parts of the grow space. 

There will be a different treatment – and prevention option – for each different pest type. So it’s certainly worth doing plenty of research to understand which species of pest is damaging your plants, and how to treat it. 

Disease can also change the appearance of your plants. Yellow areas, stunted growth and dark spots can all be signs of diseases such as mosaic virus, bacterial spot or blight. Different diseases will have different symptoms and treatments. It’s always worth doing plenty of research into the specific disease before trying to treat your plants or soil. 

Soil nutrients

Unless you’re a hydroponic grower, you’ll probably be using a combination of store-bought potting soil or soil from the garden. 

First, it’s important to make sure that you’re not using too much, or too little water. When the potting soil becomes waterlogged or over saturated, this can cause your plants to discolor or even stunt their growth. Waterlogged soil can also lead to root rot.  However, the same can happen when the soil is too compact or dry. So, it’s a real balancing act. 

It’s also worth remembering that the natural nutritional value of the soil depletes over time. Different soils will also have a different nutrient composition, with some being more acidic or alkaline than others. 

All of this can have an impact on how well your plants can absorb nutrients from the soil. 

For growers working on a large, commercial scale, it’s a good idea to invest in soil analysis before you start a new crop. This will help you to gauge the composition of the soil, and therefore how much additional fertilizer or water you’ll need throughout the growing process. 

Water

You might not realize it, but the water you use on your plants can have a huge impact on nutrient deficiency or abundance. 

Water can naturally contain contaminants, depending on the source. These contaminants can then flow into the soil you’re using and cause irrigation issues. 

Hard water, on the other hand, is likely to contain nutrients like calcium and magnesium. If you’re already using a fertilizer or nutrient mix, this will be specifically designed to incorporate the right amount of all the nutrients your plants need to thrive. Using a calcium-rich water would therefore cause an imbalance and may become toxic for your crops. Calcium is particularly risky to get wrong as a buildup of calcium sulfate can cause blockages in your growing equipment. 

Again, if you’re working commercially, or with large scale growing spaces, it’s a good idea to commission a water analyst along with your soil analysis. An analyst will be able to tell you what type of water you’re working with, and what nutrients or contaminants are naturally in the mix. 

Temperature

As you probably already know, temperature is another important factor for your grow space. The temperature of the growing environment as a whole is important, as is the root zone temperature. 

There are two different chemical processes that occur in the root zone. This is where the plants absorb both water and nutrients. Without the right root zone temperature, your plants may struggle to reach optimal health. 

The optimal temperature for the root zone is 18-22 degrees. If the root zone is too warm, you may end up starving your plants of oxygen (colder water can hold more oxygen than warm water). Similarly, if the zone is too cold, your plants may experience slower metabolic rates and as a result, their growth will be stunted. 

Checking and monitoring the temperature of your growing environment and root zone is easy. Just use a temperature meter or gauge regularly to ensure your soil never reaches out of the optimal range. If you’re struggling to cool down the grow space, check out our range of ventilation options

Nutrient strength

Obviously, taking a look at the nutrients you’re using is another key element of checking for a nutrient deficiency and diagnosing any issues your plants are experiencing.

Even with a specifically designed nutrient solution, you still need to regularly check that you’re not under or overfeeding your plants. Signs of over and underfeeding are similar, and may include things like slow or stunted growth and a scorched like appearance. 

To check nutrient strength, you can measure electrical conductivity with an EC meter. Nutrients can only be absorbed by your plants when they are formed into ions. This occurs when the nutrients are mixed or dissolved into water, and each ion has its own electrical charge. 

Measuring the electrical conductivity of your nutrients will help you to determine how strong the nutrients available to your plant are. Different plants have a different preferred EC rate, so again, you’ll need to do your own research. Some plants may even have different EC rates for different stages of the growth cycle, so it’s good to be in the know about nutrient strength every step of the way. 

Some growers recommend measuring EC on a daily basis, as it can fluctuate a lot. 

pH

The pH of your soil is one of the most integral parameters of growing to get right. You should be checking pH or a regular basis. 

If you want to know more about monitoring how pH impacts your plants, check out our previous guide here

pH is so important, as it can change the nutrients available to your plants. It can also affect how well the plants can take up the nutrients available. 

The tricky part of measuring pH is that each nutrient will have its own preferred pH for absorption. When the pH steps out of this range, your plants will suffer from nutrient lockout. 

So how can you make sure your plants are getting all the nutrients they need, at the right pH?

As a general rule of thumb, it’s recommended that you maintain a pH range of 5.8-6.5 if you’re growing hydroponically. For those using traditional potting soil, the pH can be a little higher at 6.5-7. This is because the soil can act as a small buffer is the pH becomes a little unbalanced. 

When trying to reach the optimal range, it’s important to take into consideration any other fertilizers or additives you’re wanting to use – as this again, will change the pH to add more acid or alkaline to the growing mix. While soil growers have a little leeway, unfortunately, hydroponic growers have very little room of error. 

Measuring pH should be on the top of your daily to do list. 

As always, our friendly Herbal House staff are always on hand to help! Nobody expects you to know everything all at once – so if you ever need advice or help with how to measure certain parameters, just get in touch! It’s much better to know your plant’s health is in the hands of an expert, rather than finding the first link on Google!