The perfect first aquarium... keeps fish happy, healthy and thriving.A successful aquarium requires three types of filtration. This super-efficient Eclipse Explorer provides them all .... aerating and filtering all water 17 times each hour. Mechanical Filtration: as water is silently pumped through the system, the high capacity Eclipse Filter cartridge screens out dirt, uneaten food and fish waste. Chemical Filtration: Inside the cartridge, Black Diamond Premium Activated Carbon removes dissolved pollutants which can cause discolouration and odour. Biological Filtration: Once through the cartridge, water flows over the patented BIO-Wheel, where ammonia-fighting bacteria work to remove more toxic ammonia and nitrite with every turn.Eclipse Explorer - Better than a bowl, this is the first and only 7½ litre (2 gallon) aquarium with the highly efficient Bio-Wheel 3 stage filtration system - it aerates and filters the water 17 times an hour. The textured skylight lets in surrounding light, a much better alternative to harsh incandescent bulbs that can overheat the aquarium water. Size: 28cm x 14cm x 22cm [11" x 6" x 9"] approxAquaria shown with fish, gravel and plants for illustration only.