If you’re a hydroponic enthusiast and you want to learn all the ins and outs of nutrients but don’t know where to start, you’ve come to the right place!
Nutrients — those tiny little bits of nourishment that are essential for all life on earth — are pretty sciency, yes, but don’t be too intimidated by the chemistry behind them either; they’re probably not as complicated as you think. Yes, that bottle, with all those weird letters and numbers may look pretty intense, but we promise, it’s 100% doable and completely manageable for the everyday hobbyist.
In fact, unless you’re trying to grow 10,000 plants at once, all you really need to do is follow the directions on the container and have a very “basic” understanding of the overall concept. If you do that — and learn everything you possibly can from our hydroponics hobby center — you’ll be a successful hydroponic grower in no time!
Here’s everything you need to know about hydroponics and nutrients. Read it, learn it, and start your own growing adventure!
Table of Contents:
- Why Nutrients are Necessary
- Macronutrients vs Micronutrients
- NPK Ratios
- Liquid vs Dry Nutrients
- Best Nutrient Products
- Making Your Own Nutrients
- Common Nutrient Deficiencies
Why are Nutrients Necessary in Hydroponics?
Nutrients are the foundation of hydroponics. With them, the sky is the limit. Without them, well, good luck growing anything. But why is that exactly?
Well, in order for plants to survive, they need fertilizers. And while plants normally get their nutrients from natural or synthetic fertilizers within the soil they sit in, that isn’t really an option with hydroponics. Thus, in hydroponics, plants must obtain their nutrients by other means.
Enter nutrient solutions — a concentrated mix of essential nutrients that are mixed in with water to make your plants grow. An amazing, yet incredibly simple solution with nearly unlimited potential.
Macronutrients vs Micronutrients in Hydroponics
Hydroponic nutrients are broadly categorized into two major groups: Macronutrients and Micronutrients. Both are essential for overall development and growth.
Macronutrients: are the nutrients that plants require in large amounts — includes Hydrogen, Oxygen, Carbon, Nitrogen, Phosphorous, Potassium, Magnesium, Calcium, and Sulfur.
Micronutrients: are the nutrients that plants need in small amounts — includes Iron, Manganese, Zinc, Copper, Boron, Molybdenum, and Chorine.
Important Note for Carbon, Hydrogen, and Oxygen: these macronutrients are supplied by water and air and will not be included in your nutrient solution.
Primary Macronutrients
Nitrogen (N): of all the hydroponic nutrients, Nitrogen is considered the most important macronutrient. Nitrogen is primarily responsible for leaf and stem growth, as well as overall size, vigor, and color.
Phosphorous (P): plays an essential role in photosynthesis and is also involved with energy transfer in the plant. In addition to helping form strong roots, it is crucial for the production of flowers and seeds (although it is most useful during germination, seedling growth, and budding/flowering).
Potassium (K): is necessary for every stage of growth and triggers enzymes that activate the manufacture and movement of sugars and starches. Potassium increases chlorophyll in foliage and encourages strong water uptake and root growth.
Secondary Macronutrients
Magnesium (Mg): is an atom within the chlorophyll molecule and is vitally important to the absorption of light energy as the plant grows. Magnesium helps the plant utilize nutrients and neutralize acids/toxic compounds that are produced by the plant.
Calcium (Ca): is a fundamental nutrient that helps plants grow. Concentrating itself in roots and “old” growth, calcium slowly moves through the plant and is primarily used to buffer excess nutrients.
Sulfur (S): like calcium, Sulfur moves slowly through plant tissue and plays a heavy role in root growth. Additionally, as Sulfur is involved in chlorophyll supply, it is pretty evenly distributed; however, the largest amount will go to leaves where it affects odor and flavor.
Micronutrients
Iron (Fe): used in photosynthesis, Iron is a primary catalyst in the production of chlorophyll and is a component of several enzymes associated with energy provision.
Manganese (Mn): helps produce oxygen during photosynthesis and reduces nitrates before making proteins by working with plant enzymes.
Zinc (Zn): an important nutrient for the formation of chlorophyll but must be present in very small amounts for effective plant growth.
Copper (Cu): important for plant respiration and helps with nitrogen, protein, and glucose metabolism. Furthermore, it serves as a natural fungicide.
Boron (B): in order to create cell membranes with the desired structure and functionality, calcium and boron are combined. Boron helps in seed production and pollination as well.
Molybdenum (Mo): in order for a plant to develop and function properly, molybdenum is needed to fix nitrogen from the air and convert the nitrogen that the plant absorbs into ammonia. Molybdenum is most active within seeds and roots.
Chlorine (Cl): usually not considered a plant nutrient (because it’s so abundant and will never have to be added in), chlorine helps with the transportation of nutrients throughout the plant, photosynthesis, and helps reduce the effects of fungal infections.
Understanding N-P-K Ratios
Whenever you see a container of nutrients, you’ll typically see three letters on the front — N-P-K — with three numbers associated with each letter. These numbers represent ratios for the three primary macronutrients needed for plant growth: Nitrogen (N), Phosphorous (P), and Potassium (K).
And depending on the type of plant you’re growing, each stage of the growth cycle will require a different ratio. For example, in most situations, the “N” number will be higher during the vegetative and growth stage while the “P” will be higher during the flowering stage.
Similarly, if you’ve ever looked at the front of a General Hydroponics Flora Series bottle, you’ve probably noticed that the “N” is higher on FloraMicro — because it favors early development — and the “K” is higher on FloraGro — because it favors rapidly growing plants during the structural and foliar growth phase.
Thus, at the end of the day, continually look over the bottle (of your purchased nutrients) and memorize what each ratio does.
And just to reiterate one more time, and as mentioned above, it’s probably best to just follow the directions on the back of the bottle until you get the hang of things. The directions should tell you the amount, growth stage, use, etc. (but might require a little metric conversion on your end).
Liquid vs Dry Nutrient Solutions
There are two types of hydroponic nutrients that you can purchase; those that come in liquid form and those that come in dry/powder form.
Liquid Nutrients: comes as an all-in-one plant food or a multi-part series where you can tailor the nutrients to the plant and growth stage. Considered the better option for hydroponic beginners and small-system hobbyists as the nutrients are already mixed and in liquid form.
Dry/powder Nutrients: more concentrated than liquid nutrients and have a longer shelf life. Additionally, as they’re dry and not mixed in with water, they’re usually less expensive than liquid formulas (great for commercial setups).
Best Hydroponic Nutrient Products
When it comes to hydroponic nutrient products, it really comes down to your own personal preference. However, there are three that we’ve used at Ponics Life that we believe are great for first-time growers and everyday hobbyists: General Hydroponics Flora Series, Fox Farm Liquid Nutrient Trio Formula, and AeroGarden Liquid Plant Nutrients
All three of these options should include directions and set you up for success.
Making Your Own Hydroponic Nutrients
Making your own hydroponic nutrients is completely doable, but it’s not really recommended if you’re a beginner. For obvious reasons, the professionals just do it better. But, if you’re interested in it regardless, there are plenty of YouTube videos out there that will walk you through the process step by step.
Here’s a good one to get you started.
But just remember, if you’re a hydroponic beginner, you’re going to want to see results on your first couple of grows. Otherwise, there’s a strong chance you’ll get discouraged and give up. So bottom line up front, it’s best practice to master store-bought nutrients before making your own.
Common Hydroponic Nutrient Deficiencies
As you start to grow your plants using nutrient solutions, you’ll undoubtedly run into some problems. But don’t worry too much as most issues are easily fixable, by you, the grower. For deficiencies, look for signs of stress, identify what’s happening, and then make the appropriate adjustments to your solution and/or plant.
Soluble Salts Damage
Cause: salts accumulation in aggregate media over time, over-fertilization, poor water quality, and/or inadequate leaching.
Symptoms: wilting of plants despite proper watering, dead and burned leaf margins, dark green foliage, and occasional root death.
Detection: can be detected by carefully monitoring the electrical conductivity (EC) of your water and nutrient solution.
Cure: leach with clear water, or replace with new water if applicable.
Nitrogen Deficiency
Cause: excessive leaching, under fertilization, or nutrient imbalance.
Symptoms: light green foliage, wilting, dead and/or yellow leaves, and some stunting of plants.
Detection: continually monitor and measure the electrical conductivity (EC) of your water/nutrient solution and adjust as needed.
Cure: add more nitrogen to your solution or use a mix with a higher nitrogen content.
Calcium Deficiency
Cause: under fertilization, low pH, nutrient imbalance, moisture management, low airflow, or high temperature.
Symptoms: brown leaves on new plant growth that may progress to brown dead spots. A few examples include: tip burn in lettuce and blossom end rot in peppers and tomatoes.
Detection: visually monitor for detection and look for signs of discoloration.
Cure: correct your pH to between 5.0 and 7.0, apply necessary fertilizers, make airflow uniform.
Iron Deficiency
Cause: high pH in the growing media or water or general nutrient imbalance.
Symptoms: yellowing between leaf veins (usually shows itself on new growth).
Detection: monitor water and media as necessary.
Cure: correct the pH of your nutrient solution or apply iron fertilizer if pH isn’t the issue.
Magnesium Deficiency
Cause: nutrient imbalance or high pH in media.
Symptoms: similar to an iron deficiency, you’ll see a yellowing between leaf veins; however, with magnesium deficiencies, the yellowing will occur in the lower to middle leaves.
Detection: visually monitor for detection and look for signs of discoloration.
Cure: correct the pH of your nutrient solution and apply iron fertilizer if pH isn’t the issue.
Boron Toxicity
Cause: adding too much boron to your plants (easy to do).
Symptoms: browning and/or blackening of the leaf tips and occasional death of younger shoots and leaves.
Detection: check your nutrient calculations and check levels of boron in your water before.
Cure: try to maintain concentrations below 20 ppm.
