Usually they are rated in gallons (in the US).
It's probably liters in the rest of the world.
yards, feet
they need dechlorinated fresh water, and dechlorinated salt water made with aquarium salt.
I would assume some kind of polution and syphon off the bottom of the tank and do a massive water change.
it depends on the size of the tank and what kind of conditions but generaly five or ten percent daily or weekly
An aquarium is a type of glass tank that is specifically designed to hold living water animals and plants. It typically includes features such as a filtration system, lighting, and appropriate water conditions to support aquatic life.
Symbiotic.
An aquarium thermometer typically works by measuring the temperature of the water through a sensor inside the tank. The sensor detects the temperature and displays it on a digital screen or analog scale. Some thermometers may have a probe that is submerged in the water to provide an accurate reading.
It is a Symbiotic Relationship.
Freshwater aquatic snails would be the best choice for a tank that small.
Any kind of foul smell comming from the water in an aquarium means that the water is BAD and needs replacing. It also indicates that the tank is not being looked after correctly, maybe there's rotting leftover food, maybe it's overstocked with fish, or the filter is not sufficiently large/efficient to cope with its job.
There are several places to purchase a wall aquarium. Companies such as rate my fish tank, amazon, the aquarium 101 and ebay all have products of this kind currently available for sale.
They can just live in an aquarium with the normal pebbles on the bottom that all fish live in.