A nifty sponge that is said to remove nitrates has our attention. The sponge which is supposed to be for the “Juwel” aquarium system can easily be used in a sump or other filter design. “The Juwel Nitrate Removal Sponge contains bacteria, which will after a while reduce the nitrate level in the aquarium significantly. Having removed the nitrates, which is the nutrient for the algae, they will starve or not even start to develop of this in turn will enhance the vitality of fish and plants.” Jewel then recommends to replace the sponge every 6 weeks. Whether or not this actually works or not has our avid attention. Anyone try it?