How To Bring PH Down In Hydroponics

If you’re looking to grow hydroponically, then it’s essential that you know how to bring down the pH in your water. When plants are grown hydroponically, they don’t get nutrients in the soil like they would if they were grown in soil. 

Instead, their nutrients come directly from the water. If there is too much acidity or alkalinity (or both!) in your water, then this can affect how well your plants absorb their nutrients by making it more difficult for them to absorb the nutrients from the water. 

In this article we will show you several ways that you can easily bring down ph levels on your own without having to spend money on store bought chemicals or kits!

How to Quickly Reduce the Hydroponic pH Level for Plants
Maintaining proper pH is key for healthy hydroponic plants
Several methods can lower pH in hydroponic systems
Acidic solutions like vinegar and citric acid can be used to lower pH
Many commercial products are also available to adjust pH
Always monitor pH frequently to ensure optimal conditions
Use pH down solutions gradually and carefully to avoid over-acidifying the solution


To ensure the pH of your nutrient solution is constant, you’ll need to add water that has a pH value close to 7.0. This will help keep your plants healthy and growing well.

You should use distilled water when mixing up the nutrient solution for your hydroponic garden because it’s free of impurities that can potentially harm your plants or change the pH levels in their environment. 

Distilled water doesn’t contain any minerals or chemicals that could be harmful to soil or root growth, which makes it ideal for growing hydroponically as well as organically using soil-less methods such as coco coir and aeroponics .

If you’re not sure if you want to go with distilled or reverse osmosis (RO) water from the tap, consider using rainwater instead it’s completely pure! 

Rainwater isn’t recommended for sprouting seeds because it might contain too many nutrients for fragile seedlings; however, after they’ve been transplanted into larger pots filled with potting mix , this may not be an issue anymore.

If you’re looking to add nitrogen to your hydroponic system, consider using fish waste to provide a natural source of nutrients. Check out our gardener’s advice on how to add nitrogen to hydroponics for more information and tips on nutrient management.

Baking Soda

Baking soda is a base, and it can be used to bring the ph down in your hydroponics. The amount of baking soda you need to use depends on how much you need to lower your ph. 

If you are trying to lower the ph of water from 8 down to 7, then only use about 1/4 cup of baking soda. 

If you are trying to bring it down from 10 all the way down to 6 or 7, then use up to 1 full cup. For larger containers like ponds or tanks that hold thousands of gallons, I recommend using about 2 pounds of bakingsoda per 1000 gallons of water (1 kg/1000 L).

Citric Acid

The recommended dosage for citric acid is 2 tablespoons per gallon of water. For example, if you have a 10-gallon tank with an average pH of 6.0, you would add 20 tablespoons of citric acid (or 4 tablespoons per 5 gallons). 

If you had a larger tank with 100 gallons and an average pH of 6.0, the total dosage would be 200 tablespoons (20 Tbsp per 10 gallons).

After adding your desired amount of citric acid solution, wait about 15 minutes before checking your PH again with a meter or test strips. 

If the reading indicates that there is still too much phosphate in your system’s water supply, continue adding more citric acid until it reaches the correct level (around 5-6 PPM). 

You can also use this time to make sure that everything else around your hydroponic system is working properly by testing temperature and oxygen levels as well as making sure there are no leaks on any of hoses or fittings involved in delivering nutrient solution from one part of the crop cycle to another

Root rot can be a major problem in hydroponic systems, but there are several steps you can take to prevent it. Our expert advice on how to avoid root rot in hydroponics includes tips on maintaining proper pH levels, managing nutrient solutions, and more to keep your plants healthy.

Phosphoric Acid

A weak acid is one that can lose a proton or donate it to another molecule. The strength of an acid depends on how easily it loses this proton, as well as its ability to accept a proton from another molecule. 

Phosphoric acid is very weak because it readily donates its hydrogen ion (an H+). This makes it useful for cleaning and water treatment, where you want the solution to be slightly acidic and for the pH value to change over time due to reactions with other substances in the solution. 

It can also be used in the production of phosphate fertilizers such as ammonium phosphates and superphosphate fertilizers.

Nitric Acid

Nitric acid is a strong mineral acid that’s used in the production of fertilizers, explosives, and dyes. It can also be used to dissolve metals. But be careful! Nitric acid is toxic and corrosive; it can cause burns if it gets on your skin.

Balancing pH levels is key for optimal plant growth in hydroponic systems. Our explanation on how to bring pH up in hydroponics includes step-by-step instructions and tips on using pH adjusters to keep your pH levels in the ideal range.

Hydrochloric Acid

Hydrochloric acid is a strong acid that can be used to break down organic materials. It’s corrosive and can cause burns, so it should be handled with care. 

Hydrochloric acid can also be used for cleaning concrete, removing old paint from walls, and breaking down calcium deposits in the water system.

Sulfuric Acid

Sulfuric acid is a strong mineral acid that reacts with many bases to produce sulfates, which are salts of sulfuric acid. 

It is also an important industrial chemical, used in the manufacture of fertilizers and other chemicals, as well as providing some niche uses such as etching glass for microscopy.

Sulfuric acid has both strong oxidizing and dehydrating properties. When diluted with water it can form the dilute solution called “dilute sulfuric acid,” which acts as a weak electrolyte in syndet detergents.

Fungus can be a common problem in hydroponic systems, but there are several ways to prevent it. Check out our guide on how to avoid fungus in hydroponics for tips on maintaining proper humidity and temperature levels, ensuring good air circulation, and using natural fungicides to prevent and treat fungal growth.

Lactic Acid

You can use lactic acid to lower your hydroponic solution’s pH. This is a great option if you want to grow plants, but not so great if you have an established root system or are trying to increase ph. 

If you’re interested in lowering ph and increasing ph, lactic acid may be the perfect substance for your needs!

Lactic acid is produced by the anaerobic fermentation of glucose by certain bacteria. Lactic acid bacteria do not actually produce the compound themselves they simply consume sugar and excrete it as lactic acid into their environment. 

This gives them more energy than they would get from just consuming sugar alone (and it has other uses as well). So, when we say “lactic acid” here at Stoney Hill Hydroponics Supply Co., we mean “lactate” with an “-ate” suffix—not “lactose”!

Tartaric Acid

Tartaric acid is a naturally occurring acid that comes from grapes. It can be used to lower your pH in hydroponics systems and can be added directly to your reservoir or tank. 

You must add it slowly, as too much tartaric acid will cause the water level to rise significantly. It’s also important that you understand how much you need before adding it, so be careful when using this substance.

Once you’re done adding tartaric acid, make sure that it has been diluted properly so that you don’t have any issues with leaving behind any residue when cleaning out your system later on down the road.

Managing nutrient solutions is a critical aspect of hydroponic gardening. Our expert advice on how to adjust nutrients in hydroponics includes tips on monitoring pH and EC levels, adjusting nutrient ratios, and more to promote healthy plant growth.

Malic Acid

Malic acid is a natural ingredient that can be used to lower the ph in your hydroponic system. It can be found in most grocery stores, but if you want to use it for this purpose, you should look for a food-grade version.

It’s also important to note that malic acid is not toxic to humans or plants, which means it won’t harm either the people who are consuming your produce or the fruits themselves.

Cider Vinegar (Not White Vinegar)

You can also use cider vinegar to bring down the pH, but it’s much more subtle than lemon juice.

For every gallon of water you have in your hydroponic system, add half a teaspoon of cider vinegar. This should bring your PH down by around one point on the scale. Don’t worry if it doesn’t seem like enough: you’ll be adding more shortly anyway!

It’s important to note that while apple cider vinegar has been found to be effective at lowering PH levels, it may not always be right for your crop. 

Some plants have very specific nutrient requirements and can only absorb so much calcium from their surroundings so if you’re growing anything with a high need for calcium (like tomatoes), using too much apple cider vinegar could make things worse for them by leaching important nutrients out of their roots.

Cider Vinegar as a pH Down Solution

Mildly acidic and gentle on plantsCan take longer to lower pH compared to other solutions
Inexpensive and readily availableMay not be as effective for larger systems or heavily buffered water
Contains some beneficial nutrients for plantsCan add an apple-like aroma to the water
Safe to handle and use in small quantitiesCan attract pests or microbial growth if overused
Can be used in combination with other pH down solutionsCan cause clogging or scaling in systems with hard water
Can be added periodically to maintain pH levelsMay affect the taste or nutritional quality of some crops

Lemon Juice Or Lime Juice

You can use lemon juice to bring down your pH in hydroponics. If you’re using a 5-gallon bucket or similar container, fill it up with water and add about half a cup of lemons. Let the mixture sit for an hour before adding it to your reservoir tank or soil.

Calcium Chloride

Calcium chloride is, essentially, a salt that can be used to lower the pH of water. It’s typically used in hydroponic systems when you want to bring down the pH of your water because it’s too high.

You can also use it to add calcium to your soil and prevent nutrient deficiencies like magnesium and iron deficiency.

Calcium Chloride as a pH Down Solution

Highly effective at lowering pH levels quicklyCan be dangerous if mishandled or used in excess
Relatively inexpensive and widely availableCan cause calcium buildup in some systems
Provides a source of calcium and chloride ions for plantsMay not be suitable for some plants or sensitive systems
Can be used in combination with other pH down solutionsCan be corrosive to some materials
Requires careful handling and dosing for optimal resultsCan increase salinity in the water if overused


Now, you’re ready to start bringing down that pH and make your plants happy. We hope this guide has helped you out! 

Again, remember that it’s not just about keeping your plants alive: hydroponics is all about making sure they grow as well as possible. With the right care, they can produce some amazing results and we can’t wait to see what happens next in your journey as a grower. Good luck!

Further Reading

Here are some additional resources on hydroponics and pH management:

A Guide to Different pH Down Options in Hydroponics: This article provides a detailed overview of different pH down options for hydroponic gardening, including their pros and cons, and how to use them effectively.

PH Up and Down in Hydroponics: A Definitive Guide: This comprehensive guide explains the importance of pH in hydroponics, how to adjust pH using pH up and pH down solutions, and some tips to maintain optimal pH levels for plant growth.

Hydroponic pH Problems and Solutions: This article discusses some common pH problems that hydroponic growers may encounter, how to identify them, and some effective solutions to fix them.


What is pH in hydroponics?

pH is a measure of how acidic or alkaline a solution is, and it’s critical for hydroponic gardening because the plants rely on a proper pH range to absorb nutrients effectively and grow optimally.

Why is pH important in hydroponics?

The pH level affects the availability of different nutrients in the solution. Most plants prefer a pH range of 5.5 to 6.5, and if it falls out of this range, they may not be able to absorb certain essential nutrients, leading to nutrient deficiencies or toxicities.

How do I test the pH of my hydroponic solution?

You can use a pH testing kit or a digital pH meter to measure the pH of your hydroponic solution. Make sure to calibrate your pH meter regularly for accurate readings.

How often should I check the pH of my hydroponic solution?

It’s recommended to check the pH daily, especially during the first few weeks, then weekly or bi-weekly once your plants are established.

How do I adjust the pH in hydroponics?

To adjust pH, you can use pH up or pH down solutions, which come in liquid or powder form. Follow the product’s instructions carefully and make gradual adjustments until you reach the desired pH level.