The addition of N – Nitrogen (Nitrate) and P = Phosphorus (Phosphate) is not necessary in normal community aquariums, because these substances usually end up in the aquarium in sufficient, or often even too high, volumes via the food. 
In aquascaping aquariums the situation is different. They have exceptionally high nutrient requirements due to:

• dense planting
• many fast-growing species
• high light levels (> 1 watt per litre of aquarium water)
• CO_{2-fertilisation}
• 30-50% partial water change per week
• few fish, if any, but rather shrimp and snails.

• NPK-Booster adds nitrate, phosphate and potassium in biologically balanced proportions, which means: 
  The nutrient proportions have been chosen so that all micronutrients are taken up by the plants in roughly equal proportions. This means that even with long-term, regular application both a deficiency and also the harmful accumulation of individual nutrients is avoided.