Tourmaline can release 0.06mA bioelectricity in the water and electrolyze bigger molecule group of water into smaller or single one so as to activate water. Eradiate more than 90% FIR (far infrared ray), generate above 235p/s.cm3 negative ions to make water presented alkalescence (PH is 7 ~ 7.5), antibacterial and deodorizing, and release mineral microelements. After having put tourmaline sand, water of the aquarium for fishes is activated within 2-3hours. The water molecule group becomes smaller and amount of negative hydroxide ions is increased. Water quality is clear and does not generate lichens (the top of the aquaria suffering from sunshine will once in a while generate some lichens, but they will quickly become yellow, black and die). It is very fit for survival and health of fishes.