BIOTABS – Organic Fertilisers and Soil Supplements
Biotabs fertilisers work brilliantly. And their practical application? Easy as anything! The Dutch manufacturer builds on natural processes in the soil and, as far as the operation of individual products is concerned, makes no secret of the fact that it essentially copies nature. So let nature do the work even when it comes to plants grown in pots. In addition to introducing the unique BIOTABS products, we will also bring you practical advice for growers directly from the founder of this now world-famous brand. We will therefore also touch on the topic of correct watering of plants and reveal a proven method for transplanting young plants.

Unlike controlled, human-managed indoor growing, in a forest there is no need to fertilise, measure EC or pH. This is due to an interconnected system of chemical reactions and the coexistence of micro-organisms, plants and animals, which we collectively call an ecosystem. But what if we transferred this system into indoor gardening as well? It is precisely on this idea that the founder of the Dutch company, Karel Schelfhout, explains the principles of organic growing with Biotabs products.
Micro-organisms and small creatures (for example earthworms) living in the soil eat one another while consuming organic material. Through their excrement, the soil in the wild then provides trees or plants with readily available nutrients. No chemistry is needed, and the results are even better. And so, after a quarter of a century of experience with chemical plant growing in rockwool, Karel Schelfhout decided to devote his career to developing purely natural products that would be environmentally friendly, easy to use, and above all create a natural, highly productive environment for plants grown in pots, ensuring a perfect harvest. It has worked, and that was already ten years ago. So let us introduce the complete Biotabs range in more detail. Afterwards, we will focus on the use of individual products in everyday growing practice.
Basic plant nutrition in the form of practical slow-release nutrient tablets for indoor (indoor) and outdoor (outdoor) growing is becoming increasingly popular among growers. Experienced growers appreciate the time and energy savings while achieving excellent results, and for beginners it is the perfect product that makes their first growing attempts much easier, so that they too can look forward to the harvest of their dreams, whatever the scale. BIOTABS tablets are here to make ecological growing almost child’s play, without exaggeration. To activate the tablets, simply add water; it really is that simple in practice. In addition to organic fertiliser (NPK 15-7-8), BioTabs tablets also contain beneficial bacteria and fungi, whose microbiological activity improves the substrate (soil-based or coconut) and significantly improves nutrient uptake by the plant.

We have the basics. It is also necessary to add an alternative that completely removes the need for measuring EC and pH. These are the Guerrilla tablets, which we mention at the end of this article. Below, using a practical example, you will learn how to place any fertiliser tablets into a pot. Now we move on to the other Biotabs products with which you can combine them.
Since we are on the subject of combinations, let us make a brief detour, as you occasionally ask us about combining organic and mineral products. We will answer straight away that this combination certainly does not make sense. It is necessary to realise that in organic farming and growing, from a grower’s perspective, you are not so much fertilising the plants as caring for the health of the soil environment and rich microbial life, because, as we have already explained, the soil then creates nutrition for the plants itself. And when you want to use mineral fertilisers or boosters in combination with organic products, the mineral fertilisers kill the soil life, without which this process disappears. So if you use Biotabs nutrition (or any other organic nutrition), there is no point in mixing in anything that does not have 100% natural composition. In addition, Biotabs has developed products that create a truly balanced nutritional system. If you use all sorts of different products together, this balance is unnecessarily disturbed and the results will not be as good as they could be.
This loose soil additive with a purely natural composition contains beneficial rhizobacteria, seaweed meal and humic acids (see the separate article: Fulvic and humic acids: importance and use in plant nutrition).
Among growers around the world, it is renowned for its ability, thanks to its composition, to provide an ideal environment in the soil for healthy and rapid plant development. 9 species of beneficial Endo Mycorrhiza fungi colonise the root system, whose capacity to absorb water and various nutrients from the soil increases rapidly, by up to 700%! If you read our articles regularly, you can surely already vividly imagine what this means for the health and growth rate of your plants!
Mycotrex is useful when growing in soil and in coconut substrate. It is very useful for all types of plants, from ornamental flowers to medicinal herbs and various kinds of fruit and vegetables, as well as trees and shrubs.

This 100% VEGAN liquid fertiliser for plant growing, by its composition and effects, ranks among growth and bloom stimulators. Within the comprehensive Biotabs growing strategy, it complements the products Mycotrex and Bactrex perfectly.
Its use is again completely safe for all types of plants, trees and shrubs. The natural composition consists of ingredients such as alfalfa meal, vinasse, molasses, and we must not forget the important trace elements (iron, copper, calcium, magnesium, manganese, sulphur, silicon, zinc).

Increase the fertility of the soil! The BioTabs Bactrex soil enhancer acts in the root zone of plants, where it provides them with protection against pathogens (including pythium) while also converting organic matter into nutrients. This powerful soil aid can be used to protect newly rooted cuttings or germinating seeds. In terms of consistency, it is a dry powder that dissolves easily in water. In terms of composition, expect a large amount of beneficial soil bacteria and root microbes (including 6 strains of Bacillus spp.), Trichoderma fungi and actinomycetes.
It is important to realise that Bactrex is literally a live product, and therefore you should always apply it within 6 hours of dissolving it in water.

For growers accustomed to using soil without significant pre-fertilisation or coconut substrates, which contain no nutrients, Karel Schelfhout recommends this organic blend of basic nutrients (see separate article: N-P-K - what is it?) with readily absorbable silicon (see separate article: The effect of silicon on plant health).
This natural soil improver is also rich in silicon (Si). In addition to that, it also contains fulvic acids and a heap of probiotic bacteria, whose high concentration immediately after application initiates the development of mycorrhizal fungi in the root system (see the separate article Mycorrhiza or High Yields Without Chemistry).

Biotabs boosters ensure explosive flowering!
Now it is the turn of a pair of products that Karel Schelfhout likes to compare to nitroglycerine for your bloom, in the sense of truly explosive flower development to ensure maximum yields! Although “NITRO” and “GLYCERINE” are, as is well known, an inseparable pair, the founder of Biotabs also understands that two products at once may be too much for some. In such a case, he recommends prioritising his absolute favourite product, which is the organic compost mixture PK Booster Compost Tea with a truly fantastic effect on the health and yield of cultivated plants, containing bat guano, seaweed, beneficial bacteria releasing nutrients from the soil, especially phosphorus (P) and potassium (K), as well as other special ingredients, thanks to which it brings growers results that can be seen within just a few days of the first application. At the same time, however, Karel Schelfhout emphasises that the best possible solution is the combination of PK Booster Compost Tea with the booster Bio PK 5-8, while following the application schedule below:
- PK Booster Compost Tea: week 4, week 6.
- Bio PK 5-8: week 5, week 7.
It would therefore not be effective to use both boosters together from the 4th to the 7th week of flowering.

If you are among growers who are not satisfied with watering applied only to the roots and also like to use foliar spray, you can try the effects of the foliar fertiliser Biotabs Boom Boom Spray on your plants as a powerful biostimulant containing 100% natural amino acids, peptides, glycosides and minerals.

Biotabs SeedPlugs for successful seed germination
This practical set will provide you with a quality foundation for your future harvest in 5 easy steps!
- Pour one sachet of Bio Startermix starter fertiliser into 0.5 litres of water and mix well.
- Water the SeedPlugs (the propagator with propagation cubes) with a small amount of the prepared solution and pour off any excess water from the propagator.
- It is now important to have clean hands, or to use clean gloves. You can then gently place a seed into each propagation cube, soaked with the solution, to a depth of approximately 3 mm.
- Leave the prepared propagator at a temperature of 22-24°C and after 3-5 days the seeds will begin to germinate.
- Then simply remove the germinated seeds gently together with the propagation cube from the propagator and transplant them into a 1-litre pot filled with substrate mixed with perlite (see above).

Care for seedlings with BIOTABS products
Whether you have a germinated seed in a propagation cube or already a nicely rooted larger seedling, you will later want to safely transplant the young plants into large pots. The following trio of Biotabs products will serve you perfectly for this:
Karel Schelfhout recommends a proven procedure consisting of the following steps:
- First, transplant the seedling into a small pot with a volume of 1 litre. (You will achieve even better results using HERCULES aerated pots.)
- First fill it with quality soil-based substrate, without Startrex for now.
- Then create the so-called planting hole in the middle of the pot.
- Using a spoon, first apply a small amount of Mycotrex (0.5-1.0 g), because it is important that the seedling’s roots come into contact with Mycotrex as soon as possible.
- Then gently place the rooted plant into the prepared space in the substrate with a little Mycotrex.
- Next, you need to mix and use a watering solution from 1 litre of water with the following composition: 5 ml Orgatrex + 1 g Bactrex. Both of these products help maintain optimal conditions for the soil microbiome.
- The seedling in the 1-litre pot should be watered gently with only a small amount of water.
- After 7–10 days, the small seedling or cutting will become a more mature, still-growing plant that needs to be transplanted once more, into its final pot. For a 10-litre pot, in addition to 10 litres of soil, you will need 50 grams of Startrex.
- Make a planting hole and apply 5 grams of Mycotrex into it (approximately 5 teaspoons).
- Then take 2 slow-release nutrient tablets (BIOTABS) and place them about 5 cm below the surface of the substrate.
- And now comes the prepared watering solution from 1 litre of water with the addition of 1 g Bactrex and 5 ml Orgatrex.
- You can safely water a 10-litre pot with the whole litre of watering solution. Try to pour it primarily into the places where you placed the slow-release nutrient tablets.
Further practical advice from the founder of BIOTABS
You may already have read the separate article on our blog “What water do you use to water your plants?” and perhaps also the one on reverse osmosis (RO). If not, be sure to have a look at them, because the legendary Karel Schelfhout also places great emphasis on water quality when he says: “Most people use tap water when growing plants. That may be fine, but you should keep in mind that only water that you yourself drink is good for your plants. Its EC should definitely not be higher than 0.5! When you use a reverse osmosis unit, it pays to add an extra dose of calcium and magnesium to the substrate. Classic products such as CALMAG are one option, but you can also try so-called dolomite lime, or 50 g of perlite per 10 l of substrate.
And how should plants be watered correctly? It is important to make sure, and this is even more true for large plants, that water and nutrients are readily available to the plant. Karel Schelfhout advises lifting the pot and judging whether it is heavy or not. If the pot is very heavy, the plant does not need water at the moment. If it is light, then it does. A common beginner’s mistake is to focus only on the surface of the substrate, which appears dry in the pot, and so they think something like: “Hmm, my plant needs water!” But if you lift the pot and find that it is heavy, it means your plants actually still have enough water, and by adding more water you would, on the contrary, unnecessarily expose them to the risk of overwatering.
Karel Schelfhout recommends AutoPot hydroponic systems because they require no electrical energy and, using gravity alone, work automatically so that you can be sure your plants have just the right amount of water at any given time. Plants also benefit from a stable environment, and when you water them by hand, they are sometimes too wet and sometimes too dry, whereas when you use Autopot, they will always be wet. To make them just the right level of wet, or rather moist, a 30–40% perlite mix in the substrate has proven effective when irrigating with the AutoPot system. When watering by hand, a 10% perlite mix is sufficient. This ensures that even in moist soil there is still enough available oxygen.
Read the separate article: Autopot hydroponic systems for economical operation and high yields!
Although Biotabs products are in many respects exceptional, just like other plant nutrition brands, Biotabs has also prepared cost-effective, complete fertiliser sets for customers, or the popular STARTER PACKS, which are the best way to get to know the effects of these products.

Biotabs Discovery Pack was launched only recently and is the most complete of all the sets. So if you want to try what all Biotabs products can do together during the growing cycle, we highly recommend it!
Biotabs Starterpack contains enough material for growing 5 large plants in a 10-litre pot. All you then need is the same volume of quality substrate mixed with perlite (at least 10%) for aeration. If you choose this option for the first time, here is a guide on how to make the best possible use of it straight away:
- First, manually mix the prepared substrate with perlite and 50 grams of STARTREX. 50 g corresponds to about 4 tablespoons. We recommend preparing the soil, for example on a plastic tray, not only to avoid mess, but also so that you can then move it into the pot more easily.
- Once the soil is prepared in the pot, make a planting hole in the middle and pour 5 grams of MYCOTREX into it. In this case, 5 g is 5 teaspoons.
- You can then place the plant into the planting hole prepared in this way.
- For a 10-litre pot, use 2 slow-release nutrient tablets. Place them by hand below the surface of the substrate to a depth of 5-10 cm.
- The final step is to water the pot with a watering solution of the following composition, preferably in the places where you placed the tablets:
- 1 litre of water
- 5 ml Orgatrex (The practical measuring chamber integrated into the packaging is filled with the product and then emptied after application, so there is no complicated measuring.)
- 1 g Bactrex (If there is a little more, nothing will happen; these are purely organic products, so there is nothing to worry about.)
- A frequent question is whether the BioTabs Starter Pack is also suitable for “autoflowering” varieties. The answer is a clear YES, but if it concerns autoflowering seeds, avoid transplanting. Autoflowering varieties of plants also do not particularly like receiving a large amount of nutrients right at the beginning of the growing cycle. So, for example, when growing in a 10-litre pot, use the slow-release nutrient tablets as usual, with the only difference being that you place the first tablet into the substrate right at the start of the growing cycle and the second tablet only after a few weeks. That is the only difference.

Biotabs Guerrilla Box is a simple but effective set for exceptionally easy organic growing of 5 large plants, which you can use in soil or coconut substrate. It contains a pair of products:
- Guerrilla Tabs - slow-release tablets rich in rhizobacteria, when using which there is no need to adjust pH or EC during growing. That is their great advantage. They can also be purchased separately.
- Guerrilla Juice - this liquid fertiliser creates a harmonious whole with rhizobacteria and other beneficial soil micro-organisms, including mycorrhizal fungi. It also contains a balanced amount of important trace elements.

Our TIP: Do not forget that detailed dosing tables are available for extra easy and effective dosing of Biotabs fertilisers. If you would like to ask us anything, we are here for you at the well-known e-mail address info@higarden.cz.
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What to read next:
- Beneficial micro-organisms (microbes) are indispensable helpers
- Mycorrhiza or High Yields Without Chemistry
- Hydroponics - what does it involve and how do you start?