House & Garden Algen Extract®, 5 LiterOverview Algen Extract from H&G is a Norwegian sea kelp extract that contains an abundance of macronutrients, trace elements, amino acids, natural anti biotics and vitamins. General Information Sea Kelp extracts have been used for decades as a source of nutrition for your plants. Growers using kelp based extracts note healthy, vigorous growth and an overall healthier root zone. Algen Extract is created via cold pressing which keeps the biomolecules