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Best Hydroponic Nutrients 2020: Buying Guide & Reviews

Like every living thing, plants need nutrients to survive and to grow to their full potential. Plants normally receive their key nutrients from – as I’m sure you know – the soil that they naturally grow in.

Since hydroponics is a soil-less form of growing, we have to provide developing plants with nutrients ourselves via water-soluble solutions.

So which hydroponic nutrients should you buy? It really depends on your individual hydroponic setup. Let’s go over what to consider in order to choose the best nutrient solution for your specific needs.

The following table lists our favorite hydroponic nutrient solutions:

NutrientsNPK Ratio(s)Score
1. General Hydroponics Flora Grow Series2-1-6, 5-0-1, 0-5-498%
2. Humboldts Secret Base A & B Bundle 1-4-2, 4-0-198%
3. General Hydoponics MaxiGro10-5-1496%
4. Aerogarden Liquid Plant Food4-3-692%
5. Fox Farm Trio Formula6-4-4, 0-0.5-0.7, 2-8-490%

Table of Contents:

  1. What is the NPK Ratio?
  2. What Nutrients Do Plants Need?
  3. Hydroponic Nutrients Buying Guide
  4. Top 5 Hydroponic Nutrients – Reviews

What is the NPK Ratio?

When you are shopping for nutrients you will often see three numbers printed on the bottle in this format: 4-0-8. This is the NPK ratio; NPK stands for nitrogen, phosphorus, and potassium (the most important nutrients in plant nutrition).

The numbers indicate the percentage of each element contained within the solution. For example, a fertilizer marked 4-0-8 would contain 4% nitrogen, 0% phosphorus, and 8% potassium.

What Nutrients Do Plants Need?

Plant nutrients are classified into 3 groups:

  1. Macronutrients
  2. Secondary Macronutrients (Mesonutrients)
  3. Micronutrients


These are nutrients that a plant needs in large quantities throughout its life. They are the foundation of plant growth and reproduction. 

  • Nitrogen- Nitrogen is found in every plant cell and is a major component of the chlorophyll molecule. Chlorophyll is essential in photosynthesis and it is also responsible for the green coloration of the plant, which is why plants that lack nitrogen will start to turn yellow.
  • Phosphorus- Phosphorus is proven to promote stable root systems in young plants. However, the most benefits from phosphorus are seen in the transition from the vegetative to the flowering stage. Plants lacking phosphorus will flower later than expected and provide smaller, lower quality yields.
  • Potassium- Potassium regulates the opening/closing of stomata which allow air to go in and out of the plant. Stomata are how plants obtain carbon dioxide for photosynthesis and oxygen for cellular respiration. Potassium promotes water regulation which plays a major role in both the vegetative stage and the flowering stage.

Secondary Macronutrients

Secondary macronutrients – sometimes referred to as mesonutrients – are just as vital but are required in smaller amounts.

  • Magnesium- Magnesium is located in the very center of the chlorophyll molecule, making it instrumental in the photosynthesis process. Magnesium contributes to protein synthesis and helps stabilize cell membranes preventing permanent cellular damage from disease or insects.
  • Calcium- Similar to potassium, calcium also helps regulate the stomata of a plant. Its main function is strengthening the structure of a plants’ cell walls. Strong cell walls are key in fighting off harmful bacteria, pest infestation, and environmental stress.
  • Sulfur- When sulfur is added in small amounts, it allows plants to metabolize/use nitrogen much more efficiently. Most of a plant’s sulfur is found within amino acids, the building blocks of protein. Sulfur is the main component of an enzyme that is required to create chlorophyll, making it crucial in the photosynthesis process.


Micronutrients are required in small dosages but still are important to plant health. The main micronutrients are iron, boron, chloride, copper, manganese, molybdenum and zinc.

Hydroponic Nutrients Buying Guide

There are a few important things to consider before you go buying any old nutrient solution.

Liquid or Powder?

Nutrient solutions come in two forms:

  1. Powder/Solid Solutions
  2. Liquid Solutions
powder nutrient solution

Powder solutions are cheaper, they last longer, and are better at accommodating plants with the varying nutrient requirements throughout different growth stages. This makes them the preferred choice amongst professional growers.

At a glance, they seem like the obvious choice. However, powder nutrients require more knowledge and experience to reap the full benefits. To get the best results you’ll need to know:

  • How to mix them properly. The mixing process usually consists of dissolving the nutrients within separate buckets of water and then combining them into one main nutrient solution. Some elements, like calcium nitrate, must be put in their own bucket to dissolve properly.
  • What nutrients you need. All plants need nitrogen, phosphorus, and potassium but some grow more efficiently with varying levels of meso and micronutrients. A major advantage of solid nutrients is their ability to be customized for specific crops. Companies offer formulations designed specifically for tomatoes, lettuce, and almost any crop you can imagine.
  • Different growth stages. Plants need varying ratios of nutrients throughout their lives. It is crucial to know which elements should be increased/reduced at different points throughout the growth to get the best results.

Obviously most people don’t have the time or the experience required to mix their own nutrients. This is where liquid nutrients come in!

liquid nutrient solutions

Liquid nutrients’ ease-of-use makes them the perfect choice for hobbyists & home gardeners. They come premixed into one solution. Unlike premixed powder nutrients, they arrive already dissolved in water so they are ready to use immediately.

The downside of liquid nutrients?

There are hardly any crop-specific formulations on the market. Most liquid formulations are made for general use and a lot are specifically formulated for growing marijuana.

One or Multi-Part Nutrient Solution?

One-part solutions are much easier to use but, once again, are made more for general use and can’t adhere to the different stages of growth. Despite that, gardeners do have success with using single-part, all-purpose solutions.

Multi-part liquid solutions usually consist of three different nutrient formulas. Each bottle has a unique concentration of key elements that are used at different times throughout the growth stages. 

Here’s a helpful chart that shows what nutrients plants require throughout their lives: 

Vegetative Growth StagesHigh NitrogenMedium PhosphorusHigh Potassium
Blooming Growth StagesMedium NitrogenHigh PhosphorusMedium Potassium
Flowering Growth StagesLow NitrogenMedium-High PhosphorusHigh Potassium

To better understand how multi-part solutions work, let’s take a look at a popular three-part solution set:

fox farm liquid nutrients
  1. NPK Ratio: 6-4-4. The high concentration of nitrogen and potassium in this solution makes it the perfect choice for the primary stages of a plant’s life.
  2. NPK Ratio: 0-0.5-0.7. This formula contains mostly meso/micronutrients that support healthy root systems and helps cycle the other nutrients throughout the plant.
  3. NPK Ratio: 2-8-4. As we covered earlier, plants require high levels of phosphorus and potassium as they transition from the vegetative stage to the blooming/flowering stage.

Why are EC & pH Levels Important?

EC stands for electrical conductivity. An EC meter measures the number of soluble salts (nutrients) present in your solution. The higher the EC levels, the more nutrient-rich your solution is.

However, too many nutrients in your water supply can be harmful, especially for young plants. This causes something known as nutrient burn, which starts with curling/browning of the leaves, then eventually kills the plant if not corrected. 

nutrient burn

For hydroponics, the ideal EC range is between 1.2-2.0. However, during the vegetative stages, you want to keep your EC levels between 1.2-1.6 to avoid nutrient burn.

pH stands for potential hydrogen and measures how acidic or basic a solution is. This essentially shows us how effectively the plants can uptake essential nutrients.

The ideal pH range for hydroponic plants is between 5.5-6.5. Some plants, like tomatoes, prefer more acidic conditions.

So how do you measure both EC & pH levels? A lot of companies sell sets that include both EC and pH meters for a cheap price. This 4-in-1 Set from Pancellent is accurate, easy-to-use and lasts for years.

Top 5 Hydroponic Nutrients – Reviews

Hydroponic Nutrients Comparison Chart

General Hydroponics FloraSeries
  • Form: Liquid
  • NPK Ratios: 2-1-6, 5-0-1, 0-5-4
  • Components: 3
Hubmoldts Secret Base A & B Formulas
  • Form: Liquid
  • NPK Ratios: 1-4-2, 4-0-1
  • Components: 2
general hydroponics maxigro powder nutrients
  • Form: Powder
  • NPK Ratio: 10-5-14
  • Components: 1
fox farm liquid nutrient set
  • Form: Liquid
  • NPK Ratios: 6-4-4, 0-0.5-0.7, 2-8-4
  • Components: 3
aerogarden liquid plant food
  • Form: Liquid
  • NPK Ratio: 4-3-6
  • Components: 1

General Hydroponics FloraSeries (Pack of 3)

general hydroponics floraseries nutrient solution

The FloraSeries set from General Hydroponics contains three different nutrient solutions. The three different solutions allow you to adhere to your plants’ varying nutrient needs throughout the different growth stages.

When should you use each formula? General Hydroponics has an easy-to-follow feeding chart that shows how much of each solution you should use week-to-week.

Let’s take a closer look at each individual bottle:

  1. FloraGro- NPK Ratio: 2-1-6. FloraGro is used more heavily during the early growth stages. The high concentration of potassium (6 percent) in the solution helps plants grow healthy root systems during the vegetative stage.
  2. FloraMicro- NPK Ratio: 5-0-1. Like we covered earlier, nitrogen is arguably the most important element in plant nutrition no matter what the growth stage. Since FloraMicro contains high levels of nitrogen, it should be used at a steady rate throughout the entire life cycle of the plant.
  3. FloraBloom- NPK Ratio: 0-5-4. This solution is crucial during the early to late blooming stages. The feeding chart suggests using low doses at the beginning then drastically ramping up the dosage around week 5. The increase of phosphorus and potassium will promote big, bountiful yields.

Humboldts Secret Base A & B Bundle

humboldts secret base a & b formulas

This multi-part set from Humboldts Secret is comprised of two different solutions:

  • Base A- NPK Ratio: 4-0-1
  • Base B- NPK Ratio: 1-4-2

In combination, they provide the plant with a complete profile of macronutrients: namely Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, and Fulvic Acid.

Humboldts Secret is a breeze to use because both solutions are used in equal amounts throughout the entire growing cycle. Use equal parts of Base A and Base B at a rate between 5-9mL/gallon during the vegetative stage and 9-14mL/gallon during the flowering stages.

One downside of this bundle is the lack of potassium. If you do decide to use this product, I suggest buying a high-potassium supplement to ensure healthy, timely blooms.

General Hydroponics MaxiGro

general hydroponics maxigro and maxibloom nutrients

MaxiGro has an NPK Ratio of 10-5-14. Along with a high concentration of macronutrients, it also contains important micronutrients like copper, iron, and zinc.

The high levels of nitrogen and potassium in the solution make for rapid, sturdy growth during the vegetative stages. Unfortunately, the lack of phosphorus can be a problem during the blooming/flowering stages.

This is why General Hydroponics has created another powder solution, called MaxiBloom.

MaxiBloom has an NPK Ratio of 5-15-14. If used in conjunction with MaxiGro during the early-to-late blooming stages you will see rapid growth in the size/number of your blooms.

This product is unique, as it is one of the only premixed powder nutrients available on the market. The fact it is premixed makes the dissolving process exponentially faster and easier.

Keep in mind: These solutions are sold separately.

Fox Farm Trio Formula

fox farm trio nutrient solution set

This set from Fox Farm is extremely popular and consists of their patented Grow Big, Big Bloom, and Tiger Bloom formulas.

When do you use each formula? Fox Farm also provides an in-depth feeding chart that shows when to use each solution.

Fox Farm feeding schedule

Let’s take a look at each bottle’s function:

  1. Grow Big- NPK Ratio: 6-4-4. Grow Big is rich in all three major macronutrients which boost plant size and structure during the vegetative stages. Use Grow Big up until the first signs of flowering then switch to the next solution, Tiger Bloom.
  2. Tiger Bloom- NPK Ratio: 2-8-4. It is high in phosphorus to support bountiful fruit and flowers. Tiger Bloom should be introduced at the first signs of flowering, generally around week 6. When you start using the Tiger Bloom, make sure to stop applying Grow Big for a week or so to avoid nutrient burn.
  3. Big Bloom- NPK Ratio: 0-0.5-0.7. The numbers seem low, right? This is because Big Bloom is organic, made from bat guano and earthworm castings. Big Bloom is gentle on seedlings and young plants. It promotes seed formation and also promotes multiple blooms.

Aerogarden Liquid Plant Food

aerogarden liquid plant food

Aerogarden’s patented Liquid Plant Food is a complete, one-part nutrient solution that works great with any hydroponic system, not just the Aerogarden models.

Liquid Plant Food is used from seedling to harvest, making it considerably less work than 3-part or powder nutrient products. Just follow the directions printed on the bottle, and you’ll have healthy, happy harvests without the hassle!

The solution contains all the vital nutrients in plant growth and reproduction. It has an NPK ratio of 4-3-6. This means it contains 4% nitrogen, 3% percent phosphorus, and 6% potassium. Not only that, but it also contains 1% calcium and 0.5% magnesium.