Black Pearl™

What is Black Pearl™

Grotek’s Black Pearl™ pushed BioChar into our industry as a means to improve soil quality and improve the effects of added biology to soil blends and nutrient recipes. The science of Biochar has been building in the eight years since we first launch Black Pearl™. The evidence is clear that when used properly in combination with a nutrient and soil management program that Biochar can have tremendous impact on soil quality and plant development.

Black Pearl™ is more than just high-quality Biochar. It is a highly mineralized Biochar charged with quality organic inputs like volcanic and sedimentary rock dust, natural chelates and kelp extract. The synergy between ingredients provides a dramatic boost to crops when added to any nutrient program.

Black Pearl™ is a perfect addition to any nutrient program to help boost plant growth by focusing on the quality of the soil and feeding the roots. Add it any time you are transplanting.

Key Features

  • Biological catalyst that supercharge all beneficial microbes
  • Increases nutrient availability and provides trace elements
  • Improves plant structure from roots to shoots



Remember, not all Biochar is the same and making Biochar isn’t as easy as having a fire and scooping ash and charcoal into your containers. The Biochar in Black Pearl™ is virgin wood fiber that is taken from sustainably managed forests and designed through an engineered pyrolytic process (baked without oxygen). Adding Biochar to soils increases soil carbon, and this can have a tremendous impact in several ways:

Biological stimulation

Black Pearl™ doesn’t contain any biology, but it can be an essential additive to get the most from your microbes of choice. Adding just 1% Biochar to microbial enriched soils can increase dry shoot and root weights in plants. This effect is particularly pronounced with arbuscular mycorrhizal fungi which accelerate nutrient availability. At a recommended rate of 5-10% Biochar by soil volume overall biomass can increase by 65% or more and bacteria count can increase over 130%.

Water conservation

Biochar acts like a hard walled sponge keeping water closer to roots for longer. This longer retention of accessible water helps plants maintain peak production in periods of stress and also stimulates biology to remain more active with more continuous water present in the topsoil.

Nutrient management

Biochar is used a remediation tool for the mining industry because of its ability to soak up nutrients from the surrounding soil. For growers, this means that less money washes out the bottom of your containers. For plants, it means more nutrients right when and where they need them

Stable organic matter

If you are growing outdoors, Black Pearl™ can truly shine. This product will build the long term stable organic matter than will help with soil quality for hundreds of years.   The more carbon remains in the soil; the more dramatic the benefits become regarding crop health yield and quality.


Most top soils and all potting soils are deficient in trace elements. The Industry focuses on essential elements which have been proven to necessary for a plant to achieve peak harvest. Counter to this, many studies have also shown that the additional of a broader array of trace elements can enhance production although the reasons are still not entirely clear. The Black Pearl formula brings volcanic and sedimentary rock dust together for a diverse blend of minerals perfect for stimulating microbiology and charging soils.

Natural chelates

Water soluble humic acid is a key component of the product mix. Ensuring free minerals are chelated and easier for the plants to absorb. This effect stimulates biology to expand and further assist plants in meeting their maximum potential.

Kelp Extract

When mixed with soil or dusted at the time of transplant the water soluble kelp in Black Pearl can impact plant development in terms of root biomass and leaf area index both of which lead to increases in harvested crop weight and quality. Kelp has been utilized for centuries, and this extract concentrates all of those benefits and puts them in every container of Black Pearl.

Directions for use

Black PearlTM is best applied during soil mixing or transplanting into soil and soilless media. For media mixing, work 25 ml (2 tbsp) per Liter (qt) in to the soil blend. For transplants, dust 45 ml (3 tbsp) directly under the roots and work lightly in to soil. Water thoroughly and then place plant in to transplant hole. Black PearlTM can be used as a top dress, but will be more effective when placed deeper in the Medium/Soil.

Black PearlTM Feed Chart

Soil / Soilless :4 g / 4 L (1 tsp / gal)
Hydroponics / Water Culture:

Available size


Works well with