An aquarium receptacle comprising a water purification system; a prefabricated assembly of interconnected perforate or imperforate plates adapted to be built-in within an aquarium receptacle to form a water purification system, and a set of perforate and imperforated plates for assembly to a water purification system

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Listed from its EPO record in Patent Yard's archive of European patents past their term. Its claims, description and drawings are in the EPO PDF and on Google Patents, and the Claude kit works from them.

Why it's free to use

• Filed April 24, 1987 and granted July 15, 1992. A European patent lasts at most 20 years from filing, so its term ended April 24, 2007.
• A supplementary protection certificate, which can extend a medicine or crop-protection patent, adds at most five and a half years, so even that would have ended by October 24, 2012.
• We check European rights only. A US or other national patent in its family could still be in force: check its family on Espacenet or Google Patents.