Depending on the size and type of your aquarium, you might need a external pump to provide enough power to move the water through your filtration. An external pump sucks water from the aquarium and forces is through a filtration unit or water display and returns it back into the tank. You do not need to worry about the size of the pump in relation to the size of your tank because it is external, that also leaves more room for aquatic life. Another plus is the heat from the pump is kept away from aquarium, but you have to have room for it outside of the aquarium. They are not suitable for anything less than a capacity of 75 liters.
Elements 02 - Elos Prima ...
Prima Elements is a concentrated, blend of Iodine, Bromine, Fluorine, Lithium, Molybde...