TwoTankAmin17
Fish Maniac
When water is still, it has a natural surface tension which restricts the exchange of gasses between the atmosphere and the water. In order to facilitate and maximize the exchange of gasses, oxygen in and co2 out, this surface tension must be broken. This is why it is necessary to agitate the water's surface. This can be accomplished by the rising bubbles from an airstone or sponge filter breaking the surface or by the return from a filter doing the same. Anything that causes surface aggitation will do it. However the greater the agitation, the more and faster gas excahnge can take place. In nature waves, wind, rain all act to agitate water surfaces to facilitate gas exchange.
As noted above, water temperature effects the amount of dissolved O the water can hold:
When one talks about the surface area of an aquarium effecting gas exchange, this is true to a given extent. By greatly increasing the roiling of the surface, one can increase the rate of gas exchange and overcome the limits of surface area up to a point. In some applications it is actually possible for water to become super saturated with O.
The best example of all this is found in the habitat of one of my favorite fish- the zebra pleco. They live in deepish water in a very fast flowing part of the Xingu river which has a lot of rapids. The water temperature is often above 86F (20C). In order for the fish to have enough O, it is the fast flowing rapids which insure an adequate supply. These fish are found only in one river and furthermore they are only found in one part of the river known as the big bend. The limits to their habitat are set due to the structure of the river. On either end of their fast flowing roiling water the river has areas with slower flow and much calmer stretches of water. These do not have sufficient O levels to meet the needs of the zebras. As a result these fish have not been able to move beyond the limits of their territory.
As noted above, water temperature effects the amount of dissolved O the water can hold:
When one talks about the surface area of an aquarium effecting gas exchange, this is true to a given extent. By greatly increasing the roiling of the surface, one can increase the rate of gas exchange and overcome the limits of surface area up to a point. In some applications it is actually possible for water to become super saturated with O.
The best example of all this is found in the habitat of one of my favorite fish- the zebra pleco. They live in deepish water in a very fast flowing part of the Xingu river which has a lot of rapids. The water temperature is often above 86F (20C). In order for the fish to have enough O, it is the fast flowing rapids which insure an adequate supply. These fish are found only in one river and furthermore they are only found in one part of the river known as the big bend. The limits to their habitat are set due to the structure of the river. On either end of their fast flowing roiling water the river has areas with slower flow and much calmer stretches of water. These do not have sufficient O levels to meet the needs of the zebras. As a result these fish have not been able to move beyond the limits of their territory.
