What is happening inside a pond filter?
I created this picture below to help explain what happens inside a pond filter. • Imagine the water is flowing from left to right …. • Imagine the red balls are ammonia excreted by the fish. • Also imagine water is flowing over the biomedia from left to right. • You can see lots of red ammonia molecules are flowing into the filter although they are dissolved in the water in reality. Look carefully and you will see dark grey Alfagrog biomedia underneath the coloured balls. • Look even more carefully and you might see the oxygen bubbles also dissolved in the water. • The ammonia mixed with oxygen in the water is continuously flowing across the biomedia (Alfagrog). The yellow bacteria can be seen sitting on the surface of the biomedia just waiting for ammonia and oxygen to come along. At the point where the water meets the biomedia (ie where the bacteria live) the red ammonia molecules are broken down (oxidised is the correct term) by the bacteria which keep taking deep breaths of oxyge
