Within the realm of aquarium keeping there is a vast amount and variety of equipment available to the enthusiast or professional.

Aquariums contain a finite amount of life sustaining liquid subject to evaporation, rapid temperature changes and contamination.

The four walls of an aquarium are in reality six walls with the top and bottom no less important in keeping the aquariums occupants alive.

The top of an aquarium is usually the place where things enter in and occasionally unexpectedly fly out.

It is an interesting aspect of aquarium keeping deserving it’s own place in the world of information we live in -