JBL Holiday serves for the nutrition of your fishes during the vacation. It contains all constituents, which are necessary for a healthy nutrition: Grain, fish and fish by-products, vegetable materials, yeasts and algae. JBL Holiday supplies 20-25 medium sized fish about 2 weeks long. That food stone is put in the aquarium. There it resolves itself slowly, without clouding the water. Depending on water hardness, the cubes may dissolve quicker or slower.Do you have questions about this article ?