Fertilize at your own insight


Plagron Promix is a mix of the very best, carefully selected types of peat. The addition of various types of fibre results in a lightness and oxygen level found only in Plagron quality substrates. No nutrients have been added to Promix, only Plagron worm castings. The worm castings stimulate the growth of soil organisms and activate the organic fertilizers which have to be added from the first day. This makes Promix the perfect potting soil to fertilize organically according to your own judgement and choices. The result is a 100% organic yield. Promix produces the highest yields when used with Plagron Alga Grow, Alga Bloom and the additives from Plagron.

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Because no nutrients are added to Promix, it is suitable for the more experienced grower. You are directly in control of the fertilization. So start fertilizing from day one with our organic grow phase nutrient Alga Grow.

Promix has a low EC value since it is not pre-fertilized. This is ideal for young plants, because they will experience little stress. Your plant can root quickly and therefore has a healthy basis for stable growth.

Promix is organic and certified by Control Union. This means that this substrate is suitable for organic cultivation and is good for people, animals and the environment. Promix is not pre-fertilized, contains a high organic content and is rich in soil life thanks to the added worm humus. Add organic nutrients from day one to support this soil life and your plant will grow and bloom naturally. This will benefit the taste of the final product.

Detailed info

Dosage and use

Start fertilizing the first day, for example with Alga Grow.


Peat, worm castings.
pH: 6.1 - 7.1 (1:1.5)
EC: 0.4 - 1.1 mS/cm (1:1.5)


50 L bag.

Some sizes may not be available in all countries.

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Want to create a custom grow schedule with Promix? Start right away!


Yes, technically this is possible. However, the airiness of Promix will make it difficult for the seeds or cutlings to absorb moisture. Therefore they will not develop as well and less quickly. The fibers in Promix also may hinder the seeds when they are growing out of the soil. Therefore you should rather use our Seeding & Cutting soil.

According to the 100% NATURAL Grow Style you don't have to regulate the pH and EC value of nutrient solutions when you combine Promix with Alga Grow and Alga Bloom.

You should start adding nutrition from the first day. Start off with Alga Grow and switch to Alga Bloom later. More information about dosage and type of base nutrient can be found in our grow schedule.

Yes, you can. Keep in mind that mineral base nutrients aren't organic, though. The mineral nutrients won't cooperate as effectively with the soil life in the Promix. This means that you will have to monitor pH and EC values of the nutrient water when working with Promix.
Got questions about Promix? Ask our Grow Experts!
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