External filtration device particularly for aquariums and ornamental water tanks

An external filtration device, for cleaning water of aquariums and ornamental tanks, comprising:

• a lower cup-shaped element defining a filtration chamber;
• a filtration member disposed in said filtration chamber;
• an upper cover element;
• means for detachably coupling said cover element to said cup-shaped element;
• an inlet on said cover element;
• an outlet on said cover element;
• pumping means in said cover element for driving liquid to be cleaned from said inlet through said filter member to said outlet, said pumping means having a pressure chamber;
• priming means disposed in said cover element for priming said pumping means, said priming means including a suction chamber disposed downstream of said filtration chamber and upstream of said pressure chamber, said suction chamber communicating with said pressure chamber via a passage, said suction chamber communicating with said filtration chamber via a duct having an outlet end disposed higher than said pressure chamber and said passage;
• and
• means for defining a discharge chamber communicating with said pressure chamber and said outlet and disposed downstream of said pressure chamber, said discharge chamber having a volume at least as great as a volume of said suction chamber.