House & Garden Algen Extract®, 1 LiterNorwegian sea kelp extracts are a powerful source of enrichment for your plants with tremendous benefits to your garden. Algen Extract is created by way of cold press technology, keeping the enzymes and biomolecules in the bottle active and thriving (which can't be said for similar products on the market). Norwegian sea kelp contains important macronutrients, trace elements, vitamins, amino acids, natural antibiotics the list goes on. Algen Extract