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Acidic Water For Plants: The Pros and Cons Explained


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Different types of water are used for different plants. Water used for plants can be acidic, alkaline, or neutral. Many plants prefer acidic water over alkaline. Whereas few also prefer alkaline water instead of acidic water.

Acidic water isn’t bad for all plants. Plant varieties such as tomatoes, strawberries, and raspberries grow best in slightly acidic soil with a pH of 5.5 to 6.5.

Read the article to know more about: Why do some plants feed on acidic water? How does water pH affect plant growth and development? How can you make acidic water for plants? List of plants that like acidic water. 

What is Acidic Water?

watering plants with acid water

Acidity is a measure on the pH scale that reads below the 7.0 mark.

Water with a pH of less than 7.0 is called acidic water. The more pH decreases, the more the water will become acidic. 

When applying water to my plants, I use a cost-effective and durable watering can I got on amazon which makes watering fun and easy without making a mess. You can find it by clicking here.

MyLifeUNIT Plastic Watering Can

Acidic water may contain harmful heavy metals like arsenic, cadmium, sulfur, nickel, chromium, lead, zinc, etc. Therefore, acidic water may adversely affect humans, but it does not affect the plants in the same way. 

If the acidity in water is because of weak mineral acid, the pH of the water will be 4.5 or equal to that. 

The water may become acidic because of the presence of certain metals like aluminum and trivalent iron. These metals hydrolyze in water, becoming the main cause of the acidity of water.

Weak organic acids, as well as strong mineral acid, also contribute to the acidity of water.

Weak organic acids such as tannic and acetic acid and strong mineral acids such as hydrochloric and sulphuric acid may be the prime cause of acidity in water.

However, another big reason for acidity in water is carbon dioxide which dissolves in water in the form of carbonic acid; in this way, it lowers the pH of the water. 

What’s The Best pH of Water For Plants?

pH range for plants

As per UMass Extension Greenhouse Crops and Floriculture Program, most of the plants survive best when the pH of water is between 5.5 and 7.0 (slightly acidic to neutral).  

If the pH increases, the water will become alkaline. 

Many plants also exist which require more acidic or alkaline water to grow well. The best thing about acidic water is that it is free of pollution and chlorine (Such as water from swimming pools)

Also a little to no deadly bacteria are present in such water.

However, strong acidic water having a pH ranging from 2.5 to 3.0 acts as a natural disinfectant and helps kill deadly bugs, insects, molds as well as viruses that may harm your plants. 

A handful of experts recommended using such water instead of harmful sprays to avoid harmful pathogens.

Is Acidic Water Good For Plants?

Yes, slightly acidic water between the pH range of 6.0 – 7.0 is suitable for plants. Many plants give priority to acidic water over alkaline water for better growth. This is because the acid easily liberates the soil’s ionic nutrients, making it soluble for plants to absorb.

  • One of the great benefits of using acidic water is that it helps in the germination process (the growth of a plant from a spore after a period of dormancy).
  • Acidic water is used to break down many organic minerals, so they easily get dissolved by plants. 
  • Acidic water with appropriate pH helps in boosting plant growth.
  • Acidic water helps in the fast sprouting of vegetables.
  • Tubers, bulbs, and seedlings grow well and hold roots strongly.
  • Acidic water helps in the stimulation of the blossoming of flowers.
  • The acidic water helps plants for fast blooming and aids in reviving the drooping plants.

How pH Affects Plants

The pH of the water being fed to the soil has a direct effect on how well the plant grows.

Plant nutrients are available in the soil as ionic chemical compounds. 

Soil pH affects the number of nutrients and chemicals that are soluble in soil water, and therefore the number of nutrients available to plants.

Lowering the ph of the water increases the availability of these ionic chemical nutrients for the plants to absorb via their roots.

However, if the pH of the water is too low it can actually hurt the plant by causing too many minerals to become soluble.

When this happens, the minerals are easily leached out of the soil into the drainage because the plant can only absorb a finite amount of minerals at a time.

How does Acidic water Affect Soil And Nutrient Availability

How acid water works in soil

Soil pH can affect plant growth in several ways. 

  • Bacteria that change and release nitrogen from organic matter and some fertilizers operate best in the pH range of 5.5 to 7.0, making this the optimum pH range. 
  • Plant nutrients leach from the soil much faster at pH values below 5.5 than from soils within the 5.5 to 7.0 range.
  • In some mineral soils, aluminum can be dissolved at pH levels below 5.0, becoming toxic to plant growth.
  • Soil pH may also affect the availability of plant nutrients. Nutrients are most available to plants in the optimum 5.5 to 7.0 range. 
  • PH can also affect the structure of the soil, peculiarly in clay soils.
  • In the optimum range, clay soils are granular and easy to work with. However, if the soil is either extremely acidic or alkaline, clay soils will become sticky and hard to cultivate.

How to Determine the pH of Soil

An easy and cost-effective way in determining the pH in soil is by using the pH meter from amazon. 

It is not only a pH meter, it also has a moisture meter and light sensor built-in. 

To test the moisture and pH of the soil you can use the cost-effective Trazon Soil 3-in-1 Meter. It not only tests for pH but also moisture content and light intensity. You can find it by clicking here!

Trazon Soil pH Meter 3-in-1 Soil Tester Moisture

Another more analytical way of determining soil pH is by using pH test strips. The test strips change color depending on the acidity or alkalinity of the soil sample.

Testing pH Using Soil Strips

  1. Use 2 teaspoons the soil sample
  2. Place the Soil in a Clean Glass.
  3. Add in ¼ cup of Distilled Water.
  4. Stir the soil to dissolve it in the distilled water
  5. Pour the solution through a Coffee filter
  6. Filter the liquid Into another clean container
  7. Dip the pH Test Strip into the Liquid.
  8. Note the results

We use an effective and very affordable test strip from amazon when testing our soil. You can find them by clicking here!

How To Make Acidic Water For Plants?

Most plants indeed love acidic water for better growth and nourishment. But we should also keep in mind that plants like slightly acidic water, not highly acidic. 

Highly acidic water can harm your plant as it is overloaded with acids and minerals.

Acidic water can become safe for plants if we maintain the pH of the water according to the plants’ requirements.

If the acidic water has a pH lower than 6.0, you should use synthetic magnesium oxide to raise the pH of water near to neutral. However, adding magnesium oxide may be a cause of the hardening of water.

Suppose water is highly acidic, like the pH is near 3 or 4. In that case, you can inject sodium hydroxide into the water to raise the pH of water near to neutral (pH 07), or you may convert highly acidic water into less acidic.

Important Note: You should wear protective glasses and a protective suit to avoid the contact of chemicals to your skin and eyes. 

Try to store sodium hydroxide in a cool and dry place. Also, keep sodium hydroxide away from children.

Additionally, you can add a pH-lowering solution to lower the pH. 

Finally, if you’re adding solid materials to a liquid solution, allow the material to soak in the water for a few hours to let it fully dissolve and dissociate.

Plants That Like Acidic Water (Both Alkaline and Acid):

On earth, in the kingdom of Plantae, millions of varieties of plants exist. However, all plants do not survive on the same soil or water. 

Some like neutral water, some acidic water, while others grow well in alkaline water. Below is a list of plants that like acidic and alkaline water for their survival.

  • List of Acidic Water-Loving Plants:

The plants which grow best in slightly acidic water are given below.

Cabbage(Brassica oleracea var. capitata)Onions(Allium cepa)Raspberries(Rubus idaeus)
Strawberries(Fragaria × ananassa)Beans(Phaseolus vulgaris)Apples(Malus domestica)
Grapes(Vitaceae)Carrots(Daucus carota subsp. sativus)Tomatoes(Solanum lycopersicum)
Sweet corns(Zea mays)Fothergilla(Fothergilla)Turnips(Brassica rapa subsp. rapa)
Squash(Cucurbita)Iris(Iris)Cucumbers(Cucumis sativus)
Nasturtium(Tropaeolum)Cape jasmine(Gardenia)Marigolds(Tagetes)
Heathers(Calluna)Elephant ear(Caladium)Magnolia(Magnolia)
Daffodils(Narcissus)Begonias(Begonia)Hydrangeas(Hydrangea)
Japanese andromeda(Pieris japonica)Beech trees(Fagus)Camellias(Camellia)
Dogwood(Cornus)Parsley(Petroselinum crispum)Sweet potatoes(Ipomoea batatas)
Potatoes(Solanum tuberosum)Peppers(Capsicum)Rhubarb(Rheum rhabarbarum)
Currants(Ribes)Cranberries(Vaccinium subg. Oxycoccus)Blueberries(Cyanococcus)
Elderberries(Sambucus)Broccoli(Brassica oleracea var. italica)Azaleas(Rhododendron)
Gooseberries(Ribes uva-crispa)

Is Alkaline Water Good For Plants?

The water which has a pH greater than 7.0 is called alkaline water. 

Like acidic water, some plants like to quench their thirst with alkaline water as it has multiple benefits for plant health.

  • Chlorine may prove toxic to plants’ health by burning their leaves. To avoid higher concentrations of chlorine in the water, one should water the plants with alkaline water. 
  • Alkaline water also reduces the level of fluorine. Fluorine inhibits the photosynthesis process, which harms the plant badly.
  • It helps plants to stay green and healthy without letting them dry.

Watering Plants with Acidic Water

When it comes to applying acidic water to your plants, you should be careful how it is done in order not to cause any unintentional harm and stress to the plant.

Top Watering –

Using the top watering method, water is applied from the top and by doing so can get acidic water on the leaves of the plant. 

Acid water may cause the leaves to change color or even die depending on how acidic the water is or how long it is allowed to sit on the leaves.

Therefore, if you are to water from the top we recommend using a watering can that has a long spout that could effectively channel the water to the base of the plant without touches the leaves.

There are many options out there when it comes to watering can, but we have found this affordable can that is durable and effective when watering plants without causing a mess.

You can find it on Amazon by clicking here!

Bottom Watering –

Bottom watering is an effective way of watering plants that allows the entire mass of the soil to absorb water.

This is especially useful when adding acidic water to plants. 

Here’s how to do it.

What is Bottom Watering?

Bottom watering is done by placing the plant in a tray of water at approximately 1 to 2 inches high. The water is then absorbed into the soil from the bottom up after which it is allowed to drain freely leaving the soil moist and aerated.

Bottom watering :

  • Stimulates healthy root growth
  • Prevents pests such as gnats
  • Prevents overwatering
  • Allows fresh air into the soil
Bottom watering plants infographic

Misting* – 

Misting is another effective method to water plants as it increases humidity and allows the plant to absorb water through their leaves.

However, we do not recommend using acidic water when misting as it allows the acidic water to sit on the leaves which can lead to yellowing and wilting.

The Takeaway:

As in all living organisms, water in plants contributes as much to the essential properties of life as do the sunlight, temperature, minerals, and nutrients. 

In plants, the water maintains plant temperature through transpiration and evaporation, maintains salt balance, carries nutrients, and fills several other significant roles in plant physiology.

Therefore, it is highly significant that you use the water that your plant prefers. Generally speaking, slightly acidic water has much more benefits than alkaline water. 

JayLea

JayLea has a passion for plants and has been gardening since 2015. He has valuable knowledge about gardening and houseplant care and can answer everyday practical questions that every plant owner has.

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