Hesi PK 13/14
Updated 18 Oct 2026
During the flowering period the need for phosphorus and potassium increases more and more. Flowering results in propagation, a large amount of genetic material (DNA) is built up and is accompanied by an increasing demand for energy. Both the energy molecules and the DNA strands contain a large amount of phosphate. Potassium is crucial for the transport of water and particles into the roots up to the leaves. It also regulates the uptake of carbon dioxide and influences the photosynthetic capacity.
Usage & Instructions
Use 2.5-15 ml per 10 L, increasing the dose gradually in the second half of flowering. Use only water in the last week before harvest.
Product Specifications
Description
Hesi PK 13/14 is a phosphorus and potassium supplement for the second half of the flowering phase in coco and hydro systems, used together with the bloom fertiliser.
Available variants
Fertilisers
All products in the Fertilisers range.
Hesi Bio Bloom
Bio Hesi Bloom is the flowering fertiliser of our new 100% natural, organic and vegan range. This new fertiliser meets all requirements for biological and organic cultivation, and can be recognised by the "Bio Hesi" name with the corresponding "100% natural", "vegan" and "organic farming" logo's. The raw materials used in products of this line are sustainably sourced from byproducts of food production, and 100% vegan. An example is grape pulp derived from byproducts of wine production.
Hesi Bio Grow
Bio Hesi Grow is developed with love and care, for all who want to feed crops organically, with a 100% natural product. Fully formulated with fruit and plant extracts, so it is also totally vegan. Bio Hesi's ingredients do meet all requirements to be fully permitted for organic and biological farming. The magnesium/calcium salts, as well as all the phosphates and trace elements naturally occur in soil and compost as well.
Hesi Bloom Complex
Bloom Complex is a NPK complete fertiliser with all macro and micro nutrients and additional valuable additives. Bloom Complex ensures that your plants are fully productive during the flowering period. Flowers serve the reproduction of the plant. The change from growth to flowering requires a complete reorganisation of the metabolism. The built-in pH corrector ensures optimal pH values and is thus gentle on the plants. Perfect for your plants in-house, in the garden or on your terrace. Ideal for permanent use, even in smaller pots. It keeps the root environment optimal and the soil vivid with rich microflora.
Hesi Coco
Hesi Coco fertiliser is a complete mixture with all the nutrients a plant needs for its development. The special properties of the coco substrate are fully met, regardless of whether it is used as fibre in hydroponics or as coco pulp in pot culture. Coco-medium can absorb certain minerals, this is taken into account in the fertiliser. Coco as a medium does not contain any nutrients by itself, which makes permanent fertilisation necessary. The change from growth to flowering requires a radical reorientation of all parts of the plant. The composition of our Hesi Coco is designed especially to fulfil the needs of your flowering plants in this medium. This way, your plants grown on a coco medium will flourish and blossom throughout their plant-life.
Hesi Houseplant Elixir
The special thing about houseplants is that they live in relatively small pots and therefore quickly use up all the nutrients and water. You can use this product for all cultivation methods. They come from different parts of the world and we want to supply all these different varieties with one and the same fertiliser. Therefore we developed the HousePlant Elixir, which offers the ideal nutrient supply for every indoor plant. The nutrients in HousePlant Elixir are combined in such a way that even limited environments like small pots remain vibrant.
Hesi Hydro Bloom
Hydro Bloom is a complete 1-component fertiliser that contains everything your plants need for a rich and healthy flowering season. The different hydroponic systems have one thing in common: the plant substrate is only used to fix the roots and all supply is provided by the water. All nutrients and trace elements in Hydro Bloom are formulated to be absorbed by the root system as soon as they pass through it. Do note that every hydro system is slightly different, make sure to research the specific needs of your plants.
Where to Buy
More from HESI
Other products by HESI.
Hesi Boost
Many plants need a trigger to switch from their growth phase to start their blooming phase. This can be external stimuli such as light, temperature or simply after the passage of time, but also nutritional enhancement. Boost contains a large number of natural sugars, minerals, enzymes and fruit acids from plant extracts and fruit extracts that have a strong effect on flowering.
Hesi CalMag
Hesi CalMag is a liquid calcium and magnesium supplement (5.0% CaO, 7.5% MgO, NPK 5-0-0) with iron chelate and molybdenum. It replenishes minerals missing from soft, demineralised or reverse-osmosis water, supporting strong cell walls and green leaves.
Hesi Hesilicio
Plants need more than just water and nutrients – they need power to withstand everyday challenges. Whether drought, pests, or fluctuating temperatures. That is why we are proud to add a brand new product to our range: Hesilicio. This new booster contains silicon and has been specially developed to strengthen the health and resilience of your plants.
Hesi Hydro Growth
Hydro Growth provides growing plants in hydroponic systems with the necessary nutrients in the right concentrations. Young plants have a particularly hard time in hydroponics at first, as they do not yet have many roots that can absorb nutrients. At the same time, they need a lot of energy to quickly form roots for anchoring. However, young plants in particular are very adaptable, so they can cope well with the initial acclimatisation to the artificial substrates. The vitamins and amino acids in Hydro Growth help to quickly form a healthy microfilm on the substrate. Once the roots are established, the plant is well anchored and the substrates are revitalised.
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