Pond biofilters clean up fish waste
pond, water, bacteria, fish, waste products, biofilters, chemicals, ammonia, food, garden pond, nitrates, nitrites, conversion, poison, concentrations.
Summary:
Generally speaking a garden pond has too many fish for its own good. The waste products build up in the water unless they are continuously removed.
The waste products from the fish in their initial form are mainly expressed as ammonia which is poisonous in even small quantities and especially so under certain water conditions -high pH -which will be discussed later.
Another type of bacteria also present in the biofilter then converts the nitrite chemicals into nitrate chemicals.
These chemicals are less polluting and toxic than either ammonia or nitrites -both of which are very poisonous.
The health of the pond is determined by this relentless ongoing conversion of ammonia to nitrates.
If pond water is changed frequently then to some extent the poison levels are "controlled."
The food used has a significant impact upon the amount of waste produced.
Waste products are converted to relatively harmless nitrates by naturally occurring bacteria.
Rocks, submerged trees, etc all help to purify the waste products from the fish by providing holding points for the bacteria to live on.
The more bacteria there are the better the purification.
The bacteria need oxygen to survive and they get this from the water oxygen is absorbed by the water due to the action of waves, waterfalls and wind.
A biofilter is designed to allow large concentrations of bacteria to operate effectively in a small volume within a garden pond environment.
For larger ponds the filter needs to be installed outside of the pond.