What is the pH of water and why is it important for plants?


What is the pH of the water? Water is the key element for there to be life, both animal and plant. Thanks to this vital liquid, plants can breathe, feed, grow, flourish and bear fruit. But when you grow them, you have to make sure that you use the most suitable one, because if it is too acidic or too alkaline you will have problems.

And that’s exactly where pH comes into play, also called Hydrogen ion potential (H +). The higher it is, the more alkaline it is, and the lower it is, the more acidic. But, Why is it important for plants?

What are the characteristics of the pH of the water?



The pH of pure water is 7 at a temperature of 25ºC, which means that it has a neutral pH. When it comes into contact with carbon dioxide in the atmosphere, it drops to 5,2; that is, it becomes acidic.

At first, water with a pH below 6,5 is acidic and could be corrosive. This means that it can dissolve iron, magnesium, copper, lead, and zinc, but it blocks others like calcium.

By contrast, water with a pH above 8,5 is alkaline. It dissolves calcium, potassium, and sodium, but blocks iron, magnesium, copper, lead, and zinc. In short, just the opposite that happens with acidic water.

Why is it important for plants?

Knowing the pH of the water is important when growing plants, as we will not be able to use the same to water them all. In general, those that live in temperate forests, such as Fagus sylvaticaQuercus and many Acer sp (arces), they need it to be acidic or slightly acidic to grow.

On the other hand, those that are typical of the Mediterranean, for example, such as Ceratonia siliqua (carob tree), Almond (almond tree) or Rosemary officinalis (romero), prefer neutral or alkaline water.

If we do not use the right one, problems could arise due to lack of minerals. Thus, if they lack iron, for example, we will see that their leaves begin to turn yellow, leaving the nerves clearly visible; On the other hand, if they lack calcium, their growth rate will slow down and they will acquire a sad appearance.

How is the pH of the water measured?

PH scale

pH scale

Knowing what pH a water has is very simple. Just go to the pharmacy and ask for pH strips, or buy these online, for example here!. Once we have them, We will only have to insert a strip in the glass of water, extract it and then wait to see what color it takes. Then we just have to compare it with the scale.

How to modify the pH of the water?

Upload it

To raise the pH of the water you have to mix 16 parts of baking soda with 2 parts of sodium carbonate. The first is sold in supermarkets or here!, and the second in chemical stores or here!.

Check the pH with the help of the strips.

Lower it

To lower the pH of the water, the first thing you have to do is know what its current pH is. For example, in my case the one that comes out of the house tap is very alkaline, with a pH that is around 7,5-8. Then, to lower it, what is done is to mix the liquid of half a lemon in 1l of water.

Another cheaper option if you grow a lot acid plants, is to put one or two tablespoons of vinegar in 5l of water.

You have to check the pH with the strips so that it does not drop too low.

Watering with too calcareous water is not good for acid plants

Watering with water that is too calcareous is not good for acidic plants

I hope it has served you .

What is the pH of water and why is it important for plants?

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