In the water itself, and especially on the bottom of the pond, there live billions on billions of bacteria, molds and other microscopic organisms that are able to decompose the dead plants and animals, as well as the wastes from living plants and animals.
(other microscopic organisms; are; able to decompose the dead plants and animals, as well as the wastes from living plants and animals) (billions on billions of bacteria, molds and other microscopic organisms; to decompose; the dead plants and animals, as well as the wastes)
other microscopic organisms billions on billions of bacteria, molds and other microscopic organisms
are to decompose
able to decompose the dead plants and animals, as well as the wastes from living plants and animals
the dead plants and animals, as well as the wastes