Mar 04, 2026
Version 2
Making Hoagland's Complete Nutrient Solution for Hydroponics V.2
Peer-reviewed method
- Alexander Hernandez1,
- Michael Dzakovich1
- 1USDA-ARS Children's Nutrition Research Center
- PLOS ONE Lab ProtocolsTech. support email: [email protected]
External link: https://doi.org/10.1371/journal.pone.0346497
Protocol Citation: Alexander Hernandez, Michael Dzakovich 2026. Making Hoagland's Complete Nutrient Solution for Hydroponics. protocols.io https://dx.doi.org/10.17504/protocols.io.36wgqpxp5vk5/v2Version created by Michael Dzakovich
Manuscript citation:
Shaw EA, Chandramouli SK, Dzakovich MP (2026) Layers to leaves: A suite of modular 3D printed hydroponics components for research and education. PLOS One 21(4). doi: 10.1371/journal.pone.0346497
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: March 04, 2026
Last Modified: March 04, 2026
Protocol Integer ID: 244334
Keywords: Hydroponics, Nutrient Solution, CEA, Research, Horticulture, Plant biology, Plant nutrition, Mineral nutrition, Plant physiology, Nutrition, How to make Hoagland’s No. 1 nutrient solution, Step-by-step Hoagland’s No. 1 preparation guide, Media, Nutrient solution standardization, nutrient solution, protocol further details integration of the nutrient solution, balanced nutrient environment, nutrient environment, optimal nutrient availability, hydroponic plant cultivation, nutrient uptake study, hydroponic system, strength nutrient composition, concentrated macronutrient, formulation of concentrated macronutrient, chelated iron source, application of hoagland, controlled plant growth, iron source, plant growth, ph adjustment, hoagland, nutrient solutions for hydroponic plant cultivation, hydroponic
Funders Acknowledgements:
USDA-ARS CRIS Funds
Grant ID: 3092-10700-066-001S
Abstract
This protocol describes the preparation and application of Hoagland’s nutrient solutions for hydroponic plant cultivation. The guide and examples will primarily focus on Hoagland's No. 1 nutrient solution, but information to create stock solutions for No. 2 are provided. The method outlines the formulation of concentrated macronutrient and micronutrient stock solutions, including appropriate chelated iron sources, followed by dilution to achieve the standard working-strength nutrient composition. Guidance is provided on reagent selection, dissolution order, and pH adjustment to ensure solution stability and minimize precipitation. The protocol further details integration of the nutrient solution into hydroponic systems, including routine monitoring of pH and electrical conductivity to maintain optimal nutrient availability. When prepared and managed correctly, Hoagland’s nutrient solutions provides a reproducible and well-balanced nutrient environment suitable for controlled plant growth, physiological experiments, and nutrient uptake studies.
Materials
| Stock Bottle | Molarity | Chemical | M.W. | Quanty Per Stock Solution | Full Strength Hoagland's No. 1 | Half Strength Hoagland's No. 1 | Quarter Strength Hoagland's No. 1 | |
| (M) | g/mol | g/L | mL/L | mL/L | mL/L | |||
| A | 2 | KNO3 | 101.1 | 202.2 | 2.5 | 1.25 | 0.625 | |
| B | 2 | Ca(NO3)2 · 4H2O | 236.15 | 472.3 | 2.5 | 1.25 | 0.625 | |
| C | 1 | MgSO4 · 7H2O | 246.48 | 246.48 | 2 | 1 | 0.5 | |
| D | 1 | KH2PO4 | 136.09 | 136.09 | 1 | 0.5 | 0.25 | |
| E | 0.046255863 | H3BO3 | 61.83 | 2.86 | 1 | 0.5 | 0.25 | |
| 0.009145571 | MnCl2 · 4H2O | 197.91 | 1.81 | |||||
| 0.000765111 | ZnSO4 · 7H2O | 287.54 | 0.22 | |||||
| 0.00032041 | CuSO4 · 5H2O | 249.68 | 0.08 | |||||
| 0.000119859 | Na2MoO4 · 2H2O | 241.95 | 0.029 | |||||
| F | 0.034469288 | Sprint138 (Fe-EDDHA) | 435.17 | 15 | 6 | 3 | 1.5 |
Stock solutions for Hoagland's No. 1
| Stock Bottle | Molarity | Chemical | M.W. | Quanty Per Stock Solution | Full Strength Hoagland's No. 1 | Half Strength Hoagland's No. 1 | Quarter Strength Hoagland's No. 1 | |
| (M) | g/mol | g/L | mL/L | mL/L | mL/L | |||
| A | 2 | KNO3 | 101.1 | 202.2 | 3 | 1.5 | 0.75 | |
| B | 2 | Ca(NO3)2 · 4H2O | 236.15 | 472.3 | 2 | 1 | 0.5 | |
| C | 1 | MgSO4 · 7H2O | 246.48 | 246.48 | 2 | 1 | 0.5 | |
| D | 1 | NH4H2PO4 | 115.03 | 115.03 | 1 | 0.5 | 0.25 | |
| E | 0.046255863 | H3BO3 | 61.83 | 2.86 | 1 | 0.5 | 0.25 | |
| 0.009145571 | MnCl2 · 4H2O | 197.91 | 1.81 | |||||
| 0.000765111 | ZnSO4 · 7H2O | 287.54 | 0.22 | |||||
| 0.00032041 | CuSO4 · 5H2O | 249.68 | 0.08 | |||||
| 0.000119859 | Na2MoO4 · 2H2O | 241.95 | 0.029 | |||||
| F | 0.034469288 | Sprint138 (Fe-EDDHA) | 435.17 | 15 | 6 | 3 | 1.5 |
Stock solutions for Hoagland's No. 2
Safety warnings
Please use all necessary PPE (gloves, goggles, etc.) when working with Hoagland's Solution salts, stock solutions, or complete solution.
Preparing Stock Solutions
Prior to making Hoagland's solution, 6 stock solutions (stocks A-F) need to be made ahead of time in separate glass bottles.
| A | B | C | D | E | F | G | H | |
| Stock Bottle | Molarity | Chemical | M.W. | Quanty Per Stock Solution | Full Strength Hoagland's No. 1 | Half Strength Hoagland's No. 1 | Quarter Strength Hoagland's No. 1 | |
| (M) | g/mol | g/L | mL/L | mL/L | mL/L | |||
| A | 2 | KNO3 | 101.1 | 202.2 | 2.5 | 1.25 | 0.625 | |
| B | 2 | Ca(NO3)2 · 4H2O | 236.15 | 472.3 | 2.5 | 1.25 | 0.625 | |
| C | 1 | MgSO4 · 7H2O | 246.48 | 246.48 | 2 | 1 | 0.5 | |
| D | 1 | KH2PO4 | 136.09 | 136.09 | 1 | 0.5 | 0.25 | |
| E | 0.046255863 | H3BO3 | 61.83 | 2.86 | 1 | 0.5 | 0.25 | |
| 0.009145571 | MnCl2 · 4H2O | 197.91 | 1.81 | |||||
| 0.000765111 | ZnSO4 · 7H2O | 287.54 | 0.22 | |||||
| 0.00032041 | CuSO4 · 5H2O | 249.68 | 0.08 | |||||
| 0.000119859 | Na2MoO4 · 2H2O | 241.95 | 0.029 | |||||
| F | 0.034469288 | Sprint138 (Fe-EDDHA) | 435.17 | 15 | 6 | 3 | 1.5 |
Stock solutions and Hoagland's No. 1
| A | B | C | D | E | F | G | H | |
| Stock Bottle | Molarity | Chemical | M.W. | Quanty Per Stock Solution | Full Strength Hoagland's No. 1 | Half Strength Hoagland's No. 1 | Quarter Strength Hoagland's No. 1 | |
| (M) | g/mol | g/L | mL/L | mL/L | mL/L | |||
| A | 2 | KNO3 | 101.1 | 202.2 | 3 | 1.5 | 0.75 | |
| B | 2 | Ca(NO3)2 · 4H2O | 236.15 | 472.3 | 2 | 1 | 0.5 | |
| C | 1 | MgSO4 · 7H2O | 246.48 | 246.48 | 2 | 1 | 0.5 | |
| D | 1 | NH4H2PO4 | 115.03 | 115.03 | 1 | 0.5 | 0.25 | |
| E | 0.046255863 | H3BO3 | 61.83 | 2.86 | 1 | 0.5 | 0.25 | |
| 0.009145571 | MnCl2 · 4H2O | 197.91 | 1.81 | |||||
| 0.000765111 | ZnSO4 · 7H2O | 287.54 | 0.22 | |||||
| 0.00032041 | CuSO4 · 5H2O | 249.68 | 0.08 | |||||
| 0.000119859 | Na2MoO4 · 2H2O | 241.95 | 0.029 | |||||
| F | 0.034469288 | Sprint138 (Fe-EDDHA) | 435.17 | 15 | 6 | 3 | 1.5 |
Stock solutions for Hoagland's No. 2. *Note that Stock D has been switched to NH4H2PO4 and the quantities of Stocks A and B have been adjusted slightly compared to No. 1
Stock A: 2 M Potassium Nitrate - dissolve 202.2 g of KNO3 per liter of DI water
Stock B: 2 M Calcium Nitrate Tetrahydrate - dissolve 472.3 g of Ca(NO3)2 · 4H2O per liter of DI water
Stock C: 1 M Magnesium Sulfate Heptahydrate - dissolve 246.48 g of MgSO4 · 7H2O per liter of DI water
Stock D: 1 M Potassium Phosphate Monobasic - dissolve 136.09 g of KH2PO4 per liter of DI water
Stock E: Micronutrients - dissolve 2.86 g of H3BO3, 1.81 g of MnCl2 · 4H2O, 0.22 g of ZnSO4 · 7H2O, 0.08 g of CuSO4 · 5H2O, and 0.029 g of Na2MoO4 · 2H2O per liter of DI water
You can substitute your Mo source with 0.021 g of H2MoO4 · H2O if desired
Stock F: Iron solution - dissolve 15 g of Sprint138 per L of DI water
To avoid aggregation and slow dissolving, fill a 1 L volumetric flask ~80% with DI water, place a stir bar inside and stir to create constant mixing. Slowly add pre-weighed Sprint138 over 1-2 mins ensuring that clumps do not form. Stir for 5-15 minutes until all powder is in solution, remove stir bar, and bring volume up to 1 L with additional DI water. Heating should not be required if done properly.
Sprint138 (and other iron chelators) are extremely light sensitive. Be sure to store in an amber bottle and/or wrap with foil to minimize light exposure during use/storage.
The formulation mentioned here and the quantity added equates to ~5.4 mg Fe / L of solution. Bear in mind that the use of other iron sources (e.g. Sequestrene330) need to be evaluated on a case-by-case basis to ensure stability and adequate iron bioavailability to plants.
Store all stock solutions in a refrigerator (4 ℃) until needed
Example: If one wants to prepare 500 mL of Stock D, they would first use a scale and weigh boat to weigh out 68.045 g of KH2PO4. Once they get the desired mass of crystals, they would need to add this to a 500 mL volumetric flask with ~400 mL of DI water. Then, swirl the flask enough to dissolve all the solute. Once dissolved, fill flask close to the 500 mL line and use a transfer pipette to carefully add DI water until the bottom of the meniscus reaches the 500 mL line. The solution is now ready to be poured into a glass stock bottle and be stored in a refrigerator.
Making Hoagland's Solution
When making and using work concentrations of Hoagland's No. 1 solution, first consider what strength/concentration you will need. Most plants will want to start off with quarter strength, then be moved up to half-strength after a couple of days, and then finally to full strength after a few days.
The exact timeline for increasing Hoagland's solution may depend on the plant. However, our lab has typically kept hydroponic spinach in quarter strength for 5 days, followed by half strength for 5 days, and then full strength until harvest.
Make Hoagland's solution at your desired strength based on the table in Step 1
Example: If one needs 20 liters of full strength Hoagland's No. 1 solution, they would add 50 mL of stock A, 50 mL of stock B, 40 mL of stock C, 20 mL of stock D, 20 mL of stock E, and 120 mL of stock F to one jug. Then, they would bring the total volume up to the jug's 20 liter mark with DI water.
Note: sometimes stock A may crash out of solution while being refrigerated. If this happens, make sure to redissolve the crystals. A stir bar and a little bit of heat from a hot plate should work well.
Note: the volume markings on carboys are not always accurate. To counter this, you can use a large graduated cylinder (such as a 2 liter one) to add exactly 20 liters of water to the carboy. Then, use a permanent marker to mark how high the water is. In the future, you can now use this mark as your guide when you want to make 20 liters of Hoagland's solution.
Once you are done making Hoagland's No. 1 solution, you can use a transfer pump to move the freshly made solution into your system. If there is already old solution in your hydroponic system, remove it with the transfer pump before adding your new solution.
Example setup showing transfer pump moving liquid from a carboy to a hydroponics bin. *Note: The carboy is filled with DI water for demonstration purposes only.
To use the transfer pump, start by submerging the hose on the input end of the pump into the nutrient solution. If you are not sure which end is the input end, reference the arrow on the pump. Make sure to thread the output end into the hydroponic system.
Arrow indicating flow direction of the transfer pump. use this to determine which is your input hose and which is your output hose.
Once the hose is setup, use the controller to switch the power on. On this voltage regulator, switching to the II side of the switch allows the user to control the pump's velocity. Our lab typically uses the I side of the switch which is full speed.
Transfer pump voltage regulator. The knob is set to the to a level our lab typically uses. Higher flow rates can be used as needed.
Notes: do not run the pump dry. In addition, taking advantage of gravity helps the transfer work properly, so try to have the input end of the hose at about the same elevation or higher than the output end of the hose.
To keep Hoagland's solution and hydroponic system clean, make sure to run clean, fresh DI water through the hoses and transfer pump before each time you use the transfer pump. After you finish transferring, flush out the transfer pump and hoses with a solution of 90 mL of Zerotol HC per 15 L of DI water for ~15 mins. After flushing, we recommend you disconnect the hoses from the transfer pump and then hang them up to prevent algal or mold growth from sitting water.
Once you get your plants into full strength Hoagland's solution, the solution in your hydroponic system will typically need to be replaced with freshly made Hoagland's once a week.
Nutrient solution changes should be done on an as-needed basis depending on the demands of the study. Weekly changes minimizes chances for nutrient deficiencies to occur, but are resource intensive. Less frequent changes may be suitable for many crops.
Adjusting pH of Hoagland's solution
Every time you make fresh Hoagland's solution, first use a pH meter to measure the pH. if it is at pH 5.5 +/- 0.1, no pH adjustment is needed. Otherwise, adjust the pH
Use 0.1 M potassium hydroxide and 0.2 M sulfuric acid to adjust the pH up and down, respectively.
To adjust the pH, start by using a serological pipette to add 1 mL of your acid or base directly to the jug, and then mix it in with the pH meter until you get a stable pH reading. Repeat this process until you get to your desired pH range. To speed things along, you can add more than 1 mL at a time, but we recommend you do not do more than 4 mL at a time. Also make sure to decrease how much you add at a time once you start to get close to your desired pH range. It is best to avoid overshooting when adjusting pH.
Once the solution is in the hydroponic system, check the pH once a day
If the pH is anywhere from 5.5 to 5.9, no adjustment is needed
If the pH is at 6.0 or above, adjust it down by adding 0.2 M sulfuric acid to the hydroponic system until the pH is at 5.5 +/- 0.1. Use the same method as outlined in step 14.2.
If the pH is at 5.3 or below, adjust it by adding 0.1 M potassium hydroxide to the hydroponic system until the pH is at 5.5 +/- 0.1. Use the same method as outlined in step 14.2.
The schedule for adjusting pH depends on the size and maturity of the plants. Ensure that the pH does not remain above 6.0 for long durations to avoid issues with mineral bioavailability and Fe-chelate stability.
When the plants are small and immature, the pH remains relatively stable and only needs to be adjusted once every 2-3 days typically
Once the plants are larger and more mature, the pH will often need to be adjusted on a daily basis
Note: Buffers such as MES (2(N‐Morpholino)ethanesulfonic acid)) can be used to help maintain pH at a more constant value and reduce the need for frequent, manual intervention. We have successfully grown plants with the Hoagland's Solution above supplemented with MES monohydrate at a final concentration of 2.5 mmol. For more information, please see the following article:
Bugbee BG, Salisbury FB. An evaluation of MES (2(N‐Morpholino)ethanesulfonic acid) and amberlite IRC-50 as pH buffers for nutrient solution studies. Journal of Plant Nutrition. 1985;8: 567–583. doi:10.1080/01904168509363369
Protocol references
Hoagland, D.R.; Arnon, D.I. The Water-Culture Method for Growing Plants without Soil. Calif. Agr. Expt. Sta. Cir 1950, 347.
Bugbee BG, Salisbury FB. An evaluation of MES (2(N‐Morpholino)ethanesulfonic acid) and amberlite IRC-50 as pH buffers for nutrient solution studies. Journal of Plant Nutrition. 1985;8: 567–583. doi:10.1080/01904168509363369