This substrate will buffer and maintain your pH and KH, thus creating an ideal environment for tropical fish and aquatic plants. It won’t crumble and it won’t turn into mud. But most importantly it won’t turn your tank cloudy like Fluorite does. It’s not potted soil… It’s aqua soil. How do I calculate the quantity of Soil or Soil Powder needed for my tank? Measure your tank’s length and width in cm, for example, 90 x 60 cm. Consider the thickness of the bottom layer you want, e.g. 8 cm. Make the layer thicker towards the rear wall for a great visual effect! The calculation to do is length x width x layer divided by 1000. In our example, 90 x 60 x 8/1000 = 43,2 L Soil/Soil Powder needed.