A surface filter for aquarium water purification is placed on the bottom of the aquarium that sucks the waste out of the tank to the canister filter. Small plastic pieces make and connect the main stream channels. Each plastic piece is composed of a couple of inverted pyramids that acts like a funnel. Water flows through the main channels sucked by an external filter. In the base of each inverted pyramid a small hole opens to the drainage channel, which has a hollow inverted V shape. Water, particles and fish waste are passed through the channels to the external filter. At the end of the assembly a cross channel collects the drained water. Collected water is transferred to the external filter outside the aquarium. A hose connects the external filter with the collector. Another hose is connected to the same filter to return the filtered water back to the aquarium.

The invention relates to a virus filter membrane which can be used for the removal of virus particles including parvovirus. The invention further relates to a method for producing the membrane. The membrane comprises polyacrylonitrile and polyvinylpyrrolidone.

A surface filter for aquarium water purification is placed on the bottom of the aquarium that sucks the waste out of the tank to the canister filter. Small plastic pieces make and connect the main stream channels. Each plastic piece is composed of a couple of inverted pyramids that acts like a funnel. Water flows through the main channels sucked by an external filter. In the base of each inverted pyramid a small hole opens to the drainage channel, which has a hollow inverted V shape. Water, particles and fish waste are passed through the channels to the external filter. At the end of the assembly a cross channel collects the drained water. Collected water is transferred to the external filter outside the aquarium. A hose connects the external filter with the collector. Another hose is connected to the same filter to return the filtered water back to the aquarium.

The present invention relates to a method of preparing an adsorbent for removing radon. The method includes (a) mixing a fluorine (F) compound and zeolite to produce a second mixture.