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What’s pH and why’s it important?

So you’re growing your own. You have a grow set-up and a “tomato” plant. 

And while growing your own can be a walk in the park, you need to know a few more things before you get started.

Like pH.

These two little letters are more important than you might think. pH is the acidity or alkalinity of something. 

It actively affects how well your “tomato” plants take up nutrients and minerals, and how readily available they are to your plants.

P what? 

Think of pH as temperature, and acidity and alkalinity as hot and cold—they’re two extremes, except pH describes chemicals. 

The pH scale ranges from 0.0 to 14.0, and 7.0 is neutral. Anything below 7.0 is acidic, and anything above 7.0 is alkaline (or “basic”). 

The difference between, for example, 0.0 and 1.0 or 3.0 and 4.0, isn’t just a factor of 1. Instead, each pH value below 7.0 is 10 times more acidic than the number that comes after it. 

The pH scale is a logarithmic scale.

Alright, please explain further

For example, 4.0 is 10 times more acidic than 5.0. This also means that 4.0 is 100 (10 x 10) times more acidic than 6.0, and 1,000 (10 x 10 x 10) times more acidic than 7.

Similarly, each pH value higher than 7.0 is more basic than the next. pH 9.0 is 10 times more basic than 8.0, and 100 (10 x 10) times more basic than 7.0. 

Note that we included the decimal points for the pH values we mentioned above. Because the concentration of each pH value increases tenfold, the decimal points are crucial. Even a difference of 0.3 could drastically affect your plants!

Now that we got that out of the way, why is pH important for growing “tomatoes”? 

Depending on what the pH is of your plant’s growing medium (or what you use to grow your plants in, like soil, or water, etc.), it can really affect how your plant absorbs nutrients. 

If what you grow in is too acidic, your plant will most likely wilt and die because it can’t absorb nutrients. In the same way, if what you're growing in is too basic, your plant will suffer the same horrible fate.

Most plants, including your “tomato” plant, prefer a slightly acidic pH range, between 6.0 and 7.0. 

Note that this only applies if you're using soil. If you grow in a soilless or hydroponic system, then the ideal pH range is 5.6 to 6.2. 

You may have also noticed that we've been speaking in "ranges" as opposed to suggesting that your grow system should be at a specific pH, like "just" 5.6 or "just" 6.2.

That's because your "tomato" plants don't only need just one type of nutrient or mineral—it needs a variety of nutrients and minerals to stay healthy and grow big and strong.

By ensuring that your grow system's pH stays in a range allows more nutrients to become available for your plant.

Remember? Certain pHs make certain nutrients or minerals available, so allowing for a range gives your "tomato" plant that ability to soak up more of that good stuff. 

Your soil and its pH

If you are growing in soil, you should be using good mix of soil that contains an assortment of nutrients. 

The soil can actively slow the change of your pH range, if your plant experiences any changes in its growing environment.

Sandy soils are more acidic, clay soils are more basic, and woodland soil is more neutral. 

Anything that you add to your soil can affect its pH—additional nutrients, rain vs. hard vs. clean water. 

You can test your the water that you use by testing the run-off water, which will give you a better idea of your plant’s pH as well.

Because the pH in water can change depending on where you live, the water that you use can also affect your plants. 

Natural rainwater has a pH of 5.5 to 6.0, which is, if you recall, acidic. This makes some of the nutrients that were previously unavailable, available. 

Your hydroponic system and its pH

If you have a hydroponic system, you will need to add your own nutrients, which means you’re directly controlling the pH. It’s kind of like playing god.

But, when you don’t have soil, the pH will change really fast because you have no buffer. These fluctuations will occur naturally thanks to your system’s reservoir. 

You’ll also have to monitor the pH of your system to make sure you’re not making it too acidic or too basic. Its range should be between 5.5 and 6.5. 

You can adjust pH by using pH Up (such as Potassium Hydroxide and Potassium Carbonate) and pH Down (such as Phosphoric Acid) solutions. 

With a BCNL grow box

Hydroponics is a cinch, and we try to make it as easy for you as possible. 

BCNL offers premium nutrients and offer you all the necessary equipment to give your systems the optimal pH, such as the Nutradip Tri-Meter, which will monitor temperature, nutrient content.

Yep, pH is damn important to take it into consideration when it comes to the maintenance of your grow system.

What other tips do you have regarding ensuring that your grow system has an optimal pH range?

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