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Black substrate of volcanic origin. The granules are 2-5 mm large, highly porous. 

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25,00 €

Black substrate of volcanic origin. The granules are 2-5 mm large, highly porous. Unlike silica sands, the substrate does not sag and contains enough oxygen necessary for plant roots and filter bacteria. Plant roots easily grow through the substrate and take nutrients from the bottom. In addition, better water flow ensures even nutrient and temperature distribution in the bottom.

Unlike the so-called Japanese substrates (dried enriched clays) it does not release excess nutrients into the water. There is therefore no need for an extremely frequent water change (2-3 times a week) at the beginning of the aquarium. This makes the treatment of fish and plant fertilization more complicated, for example, when over-limit fertilization with potassium is necessary.

  • Grit: 2-5 mm
  • Chemically neutral, contains only trace amounts of Fe, Mn (mmol / l)
  • The substrate is porous = does not sag, conducts nutrients and oxygen well
  • Perfect for rooting and growing plants
  • The porous substrate is an ideal home for filter bacteria that purify water = a healthy and clean environment for fish and plants
  • 100% natural
  • Holds shape - suitable for creating fancy hardscaps
  • It won't roll
  • It does not release nutrients into the water - frequent water changes are not necessary
  • Easy handling

Examples of the use of VOLCANO BLACK Rataj substrate


As a purely natural product, Volcano also contains small lava dust. However, there is no need to wash the substrate completely. Volcano is not completely chemical inert, it contains trace elements Fe and Mn. This is one of the reasons why plants grow so well. If we clean the substrate only roughly and part of the lava dust remains, it does not matter at all. Conversely, small particles are a source of immediate nutrition for plants. Only it is necessary to so prepared substrate very carefully and slowly impregnate, see. our video Creating an aquarium.

The required amount of substrate is as follows:

Length cm x depth aquarium cm x substrate height in cm: 1000 = result in liters

E.g. Aquarium with bottom dimensions 100 x 40 cm, required substrate height. The substrate depth at the front should be about 2 cm, at the rear wall 7-8 cm, so the diameter is 5 cm. For storage substrates 2-3 cm is sufficient.

100 x 40 x 5: 1000 = 20L of substrate

VOLCANO BLACK Rataj substrate does not contain any nutrients or bacteria. 

So it is good to use a storage substrate that contains nutrients that support the growth and vitality of plants. From our offer we recommend the enriched substrate  Aquaclay Ground - Old Bottom . 
We recommend using the storage substrate for demanding (high-tech) aquariums that are equipped with intensive lighting, CO 2  dosing and planted with demanding plants.
For low-tech aquariums, we recommend using Bivoj organomineral balls  , which release nutrients slowly.

The beneficial bacteria that contribute to the filtration of the water in the aquarium can be added to the aquarium using  Bactoesex . In addition to bacteria, Bactoesex contains nutrients for their rapid multiplication. Thanks to bacteria, the water in the aquarium will not only be crystal clear, but mainly "healthy".  

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