organic hydroponics cannabis

Best Hydroponic Nutrients for Cannabis?

In other words, why are some hydro nutrients better than others for growing cannabis? What kind of hydroponic nutrients need to be avoided when growing marijuana? Do you need expensive nutrients to get good results, or will cheap nutrients get the job done?

With all the different bottles of marijuana nutrients out there, how do you know which one is best for your hydroponic setup?

When it comes to choosing hydroponic nutrients for growing weed, there are a few considerations that are really important!

Best Hydroponic Nutrients

  • Made specifically for hydroponics
  • No organic matter (nutrients are provided via minerals)
  • Mineral nutrients are “chelated” (easier for plant to absorb at a greater range of pH levels)
  • Contains rich sources of micro-nutrients (to make up for what might have been found in the soil)
  • Optimum NPK ratios (more info below)

Worst Hydroponic Nutrients

  • Made specifically for soil
  • Contains a lot of organic matter (guano, worm castings, fish emulsion, blood meal, etc) – this stuff can completely mess up your reservoir and cause unexpected and unwanted bacteria/root problems. If it seems cloudy with lots of material floating in the water, don’t use it for hydro!

You can learn a lot about nutrients by looking at the label!

Optimum NPK Ratios for Hydroponic Cannabis Nutrients

N-P-K stands for Nitrogen-Phosphorus-Potassium, which are the three most important plant nutrients. These are what the 3 numbers listed on the front of all nutrient bottles stand for (Potassium is represented by “K” because chemists use the symbol K in the periodic table for potassium).

In order to get the best results growing cannabis in hydroponics, it’s important to give the right ratio of these crucial nutrients so the plant gets what it needs at the right time. For example, if you give too much Nitrogen in the flowering/budding phase, it actually surpresses bud production and reduces your yields even if the plant is completely healthy! You don’t want that!

So what are the optimum NPK values for growing cannabis in hydro?
(N-P-K are the 3 numbers on the front of nutrient bottles)

Optimal Hydroponic Cannabis N-P-K Nutrient Ratios
Life Stage N P K
Vegetative/Grow High Medium to High High
Flowering/Bloom Low High High

Additionally, hydroponic nutrients should always include….

  • Magnesium
  • Calcium
  • Iron
  • Sulfur

Nice but not necessary micro-nutrients (contained in most water sources, but if using RO or very soft water you want these in your nutrients to prevent possible deficiencies)

  • Boron
  • Cobalt
  • Copper
  • Manganese
  • Molybdenum
  • Zinc

The main difference between NPK ratios for hydro and soil are….

  • Hydro nutrients usually contain more micro-nutrients (in trace amounts), to make up for what the plant would have been able to find in the soil
  • Hydro nutrients tend to contain higher levels of Nitrogen, which is abundant in soil but not in most water sources.
  • Hydro nutrients tend to have lower levels of Phosphorus, because Phosphorus is more “available” to the plant in a hydroponic setting. In soil, there are microorganisms (as well as clay “colloidal” particles) which can ‘steal’ some of it, and soil nutrients compensate by adding more Phosphorus.
  • Hydro nutrients rarely use organic sources of nutrients. Soil nutrients often contain organic material, which can can make it easier for bad stuff to grow in a hydroponic reservoir. Organic sources of minerals also usually need to be broken down by microorganisms before the plant can absorb them, which doesn’t happen as well in a soilless environment.
  • Hydro nutrients are often made up of chelated minerals which have been specially treated so they are easier for the plant to absorb.

What are Chelated Nutrients? Manufacturers actually “wrap” the nutrients inside an organic molecule that is less affected by pH, making it easier for the plant to absorb even if the pH is too high or too low.

When set up right with good nutrients, DWC / Hydroponics can produce some incredible yields!

Optimum pH of 5.5-6.5 Recommended DWC Nutrients & Supplements

These hydroponic nutrients systems are not just great as far as cannabis yields and quality, they won’t break the bank either! There are lots of great nutrient systems out there, but the truth is that you don’t need incredibly expensive nutrients to get incredible marijuana!

The following nutrient systems have proven to thousands of growers, big and small, that they have everything needed to produce star-quality cannabis!

General Hydroponics Flora Trio Lineup

These plants grown using just the GH Trio + Hydroguard (formally known as Aquashield)
Feel free to check out the complete grow journal (over 1 lb harvest!)

General Hydroponics Flora Duo Lineup

General Hydroponics FloraDuo (Bottle A & Bottle B) ​

Hydroguard (formally known as Aquashield) – prevents and treats root rot.

House & Garden DWC Kit Lineup

Warning: H&G Products have been difficult to find online lately

The House & Garden line-up is expensive yet remarkably effective. Aqua Flakes A + B, Roots Excelurator, Algen Extract ​

Hydroguard (formally known as Aquashield) – prevents and treats root rot. No need for extra Cal-Mag with the Aqua Flakes line as it already comes with plenty!

Botanicare KIND Hydro Lineup

This is actually the hydroponic nutrient lineup I plan to use for my next grow. Right now I’m using the General Hydroponics Flora trio (which I’ve used for more than half a decade with amazing results), but I’ve decided I want to try something new and KIND is what I’ve decided to go with. I’ve heard/seen so many great things about it and Botanicare is a great company that takes feedback from cannabis growers and is happy to answer any questions if you contact them through their website.

Botanicare KIND Trio For Hydro (Base, Grow, Bloom) ​

From a grower who wrote in: “I use the Botanicare KIND lineup – it seems to get good results, not too expensive, and works very well in hydro.” Another grower told us, “As far as favorites go, I’ve been pretty pleased with Botanicare KIND, it’s ‘pretty good’ when you follow the chart, but once you start tinkering with it based on what you see with your plants, it’ll really shine since it was developed to be played with.” Apparently a lot of growers like tinkering with this trio as another grower said, “Botanicare KIND is like the opposite spectrum [of the Botanicare Pure Blend series]. The Base is just Nitrogen and Calcium. Grow and Bloom both have most of the minerals in them, along with things like seakelp! The Bloom is also 0-6-6. Grow at 2-2-4. So quite literally you can call the shots on Nitrogen and Calcium. That level of control hasn’t been around a great deal in our market. For the savvy grower this is a pretty nice tool.”

If you think you have the best hydroponic cannabis nutrients, tell us about your results!

Ever wondered what makes hydroponic nutrients "good" or "bad" for cannabis? Learn about the different types of ingredients that go into hydroponic nutrients to learn which ones work great for marijuana, and which ones to avoid!

Organic hydroponics cannabis

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You have to add to cart at least 5 bottles or any program to make checkout.

    Blog Is It Possible To Use Hydroponics To Grow Organic Cannabis?

Is It Possible To Use Hydroponics To Grow Organic Cannabis?

Published: October 3rd, 2019
Categories: Cannabis Cultivation

In today’s world of agriculture and horticulture, the term “organic” means different things to different people. While the term has historically implied the use of natural fertilisers and the avoidance of synthetic chemicals and pesticides, it has recently been adopted by hydroponic growers as well.

Depending on your definition, “organic hydroponic systems” can be used to grow a variety of plants, including cannabis. However, these systems are substantially more difficult to establish and maintain than non-organic systems. Despite this, the appeal of organically grown product is enough to lure many cannabis growers into the sphere of organic hydroponics.


Traditional organic farming has long used soil as the growth medium. However, in the modern era, many growers have rejected the use of soil and fertilisers as a defining characteristic of organic growing.

In most of the world, for a product to be certified as “organic”, it must be grown in soil. However, in 2017, the US Department of Agriculture decided to allow some hydroponic and aquaponic crops to be certified as organic. As such, some growers are now adopting these techniques as part of their organic farming programmes.

There are valid reasons why many organic growers have stayed away from hydroponics for so long. For starters, many organic nutrients are not fully soluble. They have a tendency to leave behind residual sediment that can build up inside hydroponic systems. These residuals can clog up the system, affecting its ability to grow robust, healthy plants.

Moreover, organic growing typically requires the use of beneficial microbes, and thick, sticky sugars. Similar to nutrients, these materials tend to leave behind deposits that clog up hydroponic systems. But even worse, having these deposits in your system could lead to the growth of living, thriving bacterial colonies. These kinds of growths can also affect the amount of oxygen available to roots, and consequently, your plants’ ability to grow.

Nevertheless, the probability of running into these problems can be minimised by sticking to organic hydroponic systems that are known to have a higher success rate (like aquaponics and bioponics).


There are several benefits to growing cannabis hydroponically. Hydroponic plants tend to develop faster and produce a higher yield than in soil. This occurs because nutrients can be transferred to plants much more easily in hydroponic systems than in soil. You can expect a hydroponic grow to be roughly 20% faster and more productive than soil-grown cannabis.

Moreover, hydroponic systems are more efficient with resources than soil-based grows. Hydro saves both space and water. Less water is used because it is distributed efficiently to your plants, instead of just being soaked up by the soil. Moreover, because hydroponic plants are usually grown in a sealed and protected chamber, they are less susceptible to threats like pests and disease.


There are several ways in which hydroponic systems can be modified to be more organic. However, the two most viable, successful, and widely accepted organic hydroponic systems are aquaponics and bioponics.


Aquaponic systems are hydroponics that utilise nutrient-rich fish excrement to feed plants. They rely on a system of recirculating tanks, with fish usually being kept in a specific tank with a biofilter. This biofilter uses oxygen and biological catalysts to break down nutrient particles into more manageable pieces.

Neglecting to use a biofilter could result in the residual buildup of nutrients, leading to systemic problems like microbes and algae. Some systems are built to sidestep this problem by using substrate beds to house the microbial population and avoid the biofilter altogether.

A healthy, well-established aquaponic system is perfectly capable of growing cannabis. However, it may take some time for the system to build itself up to the point where it is capable of supporting flowering cannabis plants. Many other successful and organically certified (in the US) hydroponic systems use substrate beds to promote growth. These systems use a mix of substrates including coco coir, high-quality compost, perlite, peat, and bark.


Bioponic systems work similarly to aquaponic ones, yet they do not require fish to produce nutrients. Instead, this system feeds fully soluble nutrients to plants by first passing them through a specially designed biofilter. This biofilter houses both the oxygen and microbial life required to quickly process complex nutrients into simpler forms. Moreover, bioponic systems do not use any kind of substrate. Instead of relying on microbial activity inside of a substrate, these systems rely on their biofilter.

Using a biofilter and avoiding a substrate provides the advantage of keeping the root area clear of insoluble nutrients and microbial activity, making it more clean and hygienic. Because of this, bioponic systems are considered to be more “pure” than other organic hydroponic systems. Additionally, bioponic systems will not take as long to prepare for growing cannabis as aquaponics.


There are several differences between organic and non-organic hydroponic systems that must be carefully considered when making the switch. Apart from using different (organic) nutrients, growers will also have to be mindful of differences in irrigation, pH maintenance, and disease control.

For starters, an organic hydroponic system will need to be irrigated a little differently. Drip irrigation is advised so as to avoid oversaturating the root zone. A plant’s root zone should be finely balanced between the requirements of the microbes and the root system. Organic systems will require a higher level of oxygenation at the root zone due to the number of local microbes in the area.

EC (electrical conductivity) and pH level maintenance are also handled differently in organic hydroponic systems. For instance, an organic grow tends to have naturally higher pH levels than non-organic hydroponics. However, because pH stabilising acids are not considered organic, pH levels are best left to stabilise on their own. Moreover, because organic nutrients don’t conduct electricity, EC measurements may not be very accurate or useful.

Pest and disease control will also have to be managed more carefully in organic grows. Like pH solutions, synthetic pesticides and fungicides are not considered suitable for organics. Instead, many organic growers rely on neem oil and beneficial insects to ward off unwanted pests. For the organic grower, close inspection of plant material, monitoring of plant health, and the use of sticky traps, screen vents, and double-door entries is crucial to protecting plants.


These systems are undoubtedly more challenging and demanding to build, and perhaps maintain, than regular hydroponic systems. As such, they can also be much more frustrating and time-consuming. However, if organically grown cannabis is your objective, then they just might be the perfect choice.

Organic hydroponics provides us with a cleaner, more efficient way to grow cannabis. Click here to find out how!