Everything you need to know about PH and Nutrient Availability

As you already know (or should know!) there are 9 key essentials plants need in order to thrive. The most important are light, water, oxygen, nutrients and C02. We’ve spent a lot of time in our previous posts talking about lighting and photosynthesis, so today we’re going to focus on water and nutrients. 

Why does pH matter?

When we talk about pH, we’re really talking about how acidic, or alkaline something is. And in the middle of that scale is neutral, which is typically around the 7.0 mark. Water is 7.0, while acids are measured from 6-1 and alkali 8-14.

If you’re working with a hydroponic garden, understanding the basics of the pH scale is crucial. As you’ll be omitting soil which can help balance out pH, you’ll need to keep a closer eye on the pH of both the water, and nutrients you’re using. Otherwise you could quickly find yourself with damaged roots, pest infestations and dead plants.

What pH is best for hydroponics?

The best pH for hydroponic plants is around 5.5-6.5, so you’ve got a little leeway. As you won’t be using soil, there’s already much less chance of your plants contracting diseases and pests like in traditional growing conditions. For extra protection however, a slightly acidic pH means that algae and other waterborne organisms will struggle to grow – meaning your plants won’t have to share their space or nutrients with anything else. 

Keeping your pH between 5.5 and 6.5 also prevents nutrient lockout, where your plants can no longer take up the nutrients they need. 

How to give your plants the nutrients they need

In one of our previous posts, we’ve highlighted all the nutrients plants need to grow. The pH of your nutrient reservoir affects how accessible these nutrients are for your plants. If the reservoir has a pH that is too high or low, your plants will lose their ability to absorb nutrients and completely shut down. Not ideal. 

That’s why understanding the pH of your nutrients, along with the water you’re using is integral for successful hydroponic plant growth. Your water, and the nutrient solution need to be within the 5.5-6.5 range in order to create a balanced environment for your plants to thrive in.

As different amounts of nutrients can be absorbed at different pHs, it’s generally recommended to keep the pH at around 6.2 as this is the ‘sweet spot’ for hydroponics. However, this is a general recommendation, and it’s worth doing additional research into the specific type of plant you’re looking to grow. 

PH Buffers

When buying liquid nutrients, most come with their own pH buffer, to make it easier for you to ensure your plants have the optimum levels for absorption. These buffers rebalance the pH of your water, making it a little bit easier to manage. However, you should still manually monitor the pH yourself. As your plants begin to take in water and nutrients, the pH can quickly fluctuate, so you’ll need to keep a pH testing kit to hand. 

So, that’s all you need to know for beginning your next hydroponics project!