Complete Guide On The Best pH Level For Hydroponics

Without the proper pH level for hydroponics and the plants in those systems you just won’t see a thriving garden.

It’s often an overlooked part of gardening with hydroponics but we’ll tell you how to get a properly balanced nutrient mix for several different types of plants. And all without needing a chemistry degree to understand!

Let’s get into it.

What’s The Meaning Of pH In Hydroponics?

A pH value in hydroponics measures how acidic or alkaline your water and nutrient solution is on a scale of 0-14. With the lower value being more acidic and the higher value more alkaline. Pure water is 7.0 which is considered pH neutral.

The proper value varies for different types of plants, as they require a different set of nutrients. So, if your pH is too low or too high, you might actually prevent the plant from absorbing the nutrients where it won’t be able to grow properly.

This is often an overlooked aspect of a hydroponic system as most people focus on the nutrients alone.

It’s essential to know the pH levels that different plants require and to test your nutrient water to see if you need to adjust pH.

Ideal pH Levels For Hydroponics

In general, the most beneficial pH range for hydroponics is from 5.5 to 6.5. Still, it’s not the same for every plant type, as we already discussed. 

You might notice the optimal pH range for growing berry fruits is from 4.0 to 5.0, while pumpkins and mints could use a level as high as 7.5 or even 8.0.

The lower the pH range is, the more acidic your nutrient solution will be. The nutrient solution pH level determines the overall availability of the nutrients, so making sure the pH levels are correct is crucial. If you don’t get this right, your plant will show growth deficiencies that reflect on the leaves and the fruits.

Luckily, it’s possible to adjust pH levels and frequently measure the pH of your nutrient solution to encourage proper growth.

Measuring The Nutrient Solution With pH Meter

To adjust the pH in your system, you’ll first have to measure it and determine its current value on a ph scale. This can be done with the pH test kit that comes with a pH-sensitive strip you can use for testing.

Once the strip comes in contact with your nutrient solution water, it will change color and you can compare it with the pH chart on the bottle to see the pH level.

Also, you can use a digital pH meter and this is perhaps the most reliable option. They are more precise than the strip variants, and you will see the pH value of your nutrient tank displayed on a digital screen, so it removes any guess work of matching up colors on a strip.

Based on the reading from the meter, you can use different solutions for raising or lowering the pH level. Because of the precision required to properly adjust the nutrients, using digital pH meters as a pH testing solution is the best option.

Adjusting The pH Range In Hydroponics

Now that you know how pH affects your nutrient tank and hydroponic system in general, it’s time to deal with the adjustments. After conducting a test with your pH meter, you might need to lower it or raise it.

Luckily, there are numerous pH solutions for adjusting your nutrient solution pH. On top of the chemicals you can use, there are also some options you can find in your kitchen or household to reduce or raise the pH.

Lowering pH Levels

When adjusting pH levels, it’s crucial that you know the right solutions and their measurements. To lower the pH, you’ll need to add acid into the mix, and you can find commercial adjuster kits to do so.

These will usually be designated with a “pH Down” mark. They might include compounds like Phosphoric acid and affect the acidity of your nutrient solution water with every drop. That’s why it’s important not to overdo it and to measure the pH every step of the way.

If you are only using a gallon of water in a small hydroponic system, a few tablespoons of the pH Down solution should do the job. You can see the pH range dropping from over 7.0 to an optimal pH range of 5.0 to 5.5 with a few tablespoon drops.

On the other hand, you won’t have to go that far and buy a commercial solution for lowering the pH, especially in smaller hydroponic systems. You can also use vinegar to reduce the pH level in a nutrient mix.

Vinegar is acidic in nature and will impact the pH reading in the same way as a few drops of pH Down solution would. A couple of tablespoon measures are more than enough to significantly lower the pH level.

Finally, you can also lower your pH levels by using a single lemon. Lemon juice is also acidic and you can squeeze just one lemon and add the juice into the mix to adjust pH and reduce it in the mix.

Raising pH Levels

Sometimes you may find your solution needs to be more alkaline or maybe you lowered the pH level a little bit too much and need to raise it back up, you can do that by adding a basic solution which will increase your pH levels. 

Overall, an alkaline or basic nutrient mix will have a pH measurement of over 7.0 from the start.

The optimal pH is usually lower than that limit, but it all depends on the type of plant you are growing. Daylillies, lavender, and some rose species thrive in high pH solutions that range up to 8.0.

So, if you want to raise the alkalinity of your nutrient mix, you can use a commercial solution usually designated as “pH Up”. These solutions often contain Potassium hydroxide or Potassium carbonate as basic compounds.

You should also measure the pH both before adding the solution and after, as just a few drops can make it go up drastically in nutrient tanks with one gallon of water. 

You can also use some household-found ingredients like baking soda to raise the pH of your nutrient mix.

The Ideal pH For Hydroponic Crops

The most common pH level for hydroponic plants is usually in the range of 5.0 to 7.0, but it also greatly depends on the specific plant type. As the pH levels range from 0 to 14, you have to know the exact range that suits every plant.

Here’s an overview of the best pH levels for different types of plants:

Plants That Thrive In 5.0 to 6.0 pH Range

Leafy greens and similar veggies thrive best in the pH level range from 5.0 to 6.0, while a lot of these plants can also handle slightly higher pH levels. Still, keeping it in this optimal range is best for growing these hydroponic plants:

• Basili

• Lemon balm

• Cucumber

• Eggplant

• Lettuce

• Melon

• Mint

• Parsley

• Spinach

• Watermelon

• Beans

• Cucumber

Plants That Thrive In 6.0 to 7.0 pH Level

Some fruits and veggies grow best between pH levels of 6.0 to 7.0. The neutral pH level is also perfect for growing roses and other flowers, so here’s a list of the plants that thrive in these hydroponic pH conditions:

• Bell Peppers

• Cauliflower

• Broccoli

• Celery

• Lavender

• Peas

• Swiss Chard

• Watercress

• Roses

Plants That Thrive In Alkaline pH Levels

Hydroponic gardening can be tough without proper knowledge of acidic and alkaline pH levels that suit specific plants. As we’ve covered acidic and neutral pH level plants, these are the hydroponic plants you can grow at a slightly alkaline, or basic, pH:

• Pumpkins

• Brussel Sprouts

• Pak Choi

Final Thoughts

Now that you know why adjusting pH levels in a hydroponic system is crucial to avoiding nutrient deficiencies, you can start to get your hydroponic garden into optimal pH ranges. 

While the typical pH ranges are between 5.5 and 6.5, some plants might need a slightly different pH level.

Rely on this guide to achieve healthy growth and always check the pH readings to adjust your nutrient solution as needed.

Frequently Asked Questions (FAQ):