Aquarium lighting system and method for operating an aquarium

Abstract

A mobile aquarium includes a display tank mounted on a wheeled cart and a system for lowering the center of gravity of the aquarium. In one embodiment, the system for lowering the center of gravity uses a storage tank that is lower than the display tank. The system transfers water from the display tank to the storage tank for moving. The lower water level in the display tank is kept high enough to provide a livable habitat for fish in the display tank. A background lighting system for the aquarium includes a light source and a semi-opaque sheet with a first image on a first side and a second image on a second side. The light source illuminates the sheet so that the second image shows through the first side of the sheet and appears behind the first image. In one embodiment, the first image has a graduate color that is lighter at one end than the other.

I claim:  
     
         1 . An aquarium comprising: 
 a cart having wheels; and    a display tank that is attached to the cart.    
     
     
         2 . The aquarium of  claim 1 , further comprising a system for changing the center of gravity of the aquarium.  
     
     
         3 . The aquarium of  claim 2 , wherein: 
 the aquarium has a first configuration for viewing of contents of the display tank and a second configuration for moving the display tank; and    the system for changing the center of gravity operates to change the aquarium between the first configuration and the second configuration.    
     
     
         4 . The aquarium of  claim 1 , further comprising: 
 a storage tank; and    a fluid transfer system connected to the display tank and the storage tank.    
     
     
         5 . The aquarium of  claim 4 , wherein in the fluid transfer system operates to transfer fluid between the display tank and the storage tank to switch the aquarium between a first configuration for viewing of contents of the display tank and a second configuration for moving the display tank.  
     
     
         6 . The aquarium of  claim 5 , wherein in the first configuration, the display tank has a first water level that is higher than a second water level of the second configuration.  
     
     
         7 . The aquarium of  claim 6 , wherein the second water level is sufficient to provide a livable habitat for fish in the display tank.  
     
     
         8 . A method for moving an aquarium, comprising: 
 placing a display tank in a cart having wheels;    placing a storage tank in the cart at a level lower than that of the display tank;    transferring water from the display tank to a storage tank on the cart, wherein transferring the water lowers the center of gravity of the cart, the display tank, and the storage tank combined;    rolling the cart to a new location; and    transferring water from the storage tank to the display tank.    
     
     
         9 . The method of  claim 8 , further comprising placing living creatures in the display tank wherein the living creatures remain in the display tank during the transferring of water and the rolling of the cart.  
     
     
         10 . The method of  claim 8 , placing the display tank in the cart comprises attaching the display tank to the cart.  
     
     
         11 . A lighting system for an aquarium, comprising: 
 a sheet having a first image on a first side and a second image on a second side, the first side being disposed adjacent the aquarium;    a light source behind the second side of the sheet, wherein when the light source is turned on the second image is visible from the first side of the sheet.    
     
     
         12 . The lighting system of  claim 1   1 , wherein first image has graduated a shading from a lighter color near a top of the aquarium to a darker color near a bottom of the aquarium.