Underwater apparatus for an aquarium and related methods

In combination:

• an aquarium comprising a bottom wall peripherally bounded by upstanding side walls for holding water to a predetermined water level;
• an underwater refuge positioned in a submerged state within the aquarium for permitting submerged amphibious life to selectively leave a water environment for an air environment, the underwater refuge further comprising:
• a housing defining a chamber, the housing having an upper portion and a lower portion;
• a water door between the upper portion and a lower portion whereby water exists in a lower part of the chamber;
• a pump in fluid communication with the chamber for pumping a gas into the chamber, to create an environment comprising a volume of gas above the water in the chamber;
• an adjustable valve in fluid communication with the housing for discharging gas from the chamber at a desired adjustable rate;
• wherein the amounts of water and gas within the chamber may be adjustably controlled.

An underwater refuge for permitting submerged amphibious life to selectively leave a water environment for an air environment while still submerged comprising:

• a contained volume of water comprising a top water surface;
• a submerged housing within the volume of water beneath the top water surface;
• an air chamber within said housing;
• a water door permitting water to enter the lower portion of the air chamber, wherein the water door permits amphibious life to enter and exit the air chamber;
• a source of air under pressure from which air is delivered to the air chamber along a flow path, by which a submerged air environment is created and maintained;
• a valve in fluid communication with the air chamber by which air is discharged from the air chamber and the pressure of the air within the air chamber is maintained at a desired magnitude.

An enhanced aquarium apparatus comprising:

• an aquarium;
• a hollow chamber submerged in the aquarium, the chamber comprising a hood and a base, the hood defining a plurality of entryways to permit amphibious creatures to enter and exit the hollow chamber;
• a source of gas under pressure and gas flow path structure spanning between the source and the chamber to selectively introduce gas under pressure into the chamber;
• a gas effluent control associated with the hood and the gas under pressure therein through which the gas under pressure is selectively released into the aquarium.