Ammonia Removal. Some quick notes

Ways Ammonia can be removed from a fish tank.

1. Water changes.
This is effectively serial dilution to address a transient problem. It does not address a continuing problem.
Reducing ammonia by dilution is a useful method , but trying to recover a tank with a high ammonia reading using water changes will demand some very large water changes.
Efficiency is low.

2. De-gasing by aeration
This will have a number of purposes….not only will it help remove ammonia but will also facilitate the increase in oxygen required by anaerobic nitrosofying bacteria.
Efficiency is low.

3. Molecular-Sieve/Catalytic-Site/Exchange-Resin removal.
This is a mixed group of substances that physically remove ammonia from solution by means of adsorption, chemical absorption, or acting as a catalyst.
Products such as Polyfilter and Ammonia Adsorbing Zeolites/Resins are classes within this broad group.
Ammonia removed by these will not be detected in an ammonia test kit as the ammonia-nitrogen is no longer within the water.
Very efficient and rapid. Useful for emergencies, but their activites are not sustainable (they become exhausted with time).

4. Chemical Chelation
These chelate the ammonia in a complex that effectively removes ammonia from affecting the fish.
The ammonia-nitrogen still remains in solution and, thus, released at high pH under many ammonia test kit conditions (ie test kits may still give a positive reading for ammonia).
Some products require additional increased aeration.
Medium efficiency and not sustainable (ie they have an emergency use only).


5. Physical Changes to proportion of free Unionised Ammonia
Reducing pH and reducing temperature will drive the equilibrium of unionised ammonia and the less toxic ionised ammonia (=ammonium) towards ionised ammonia (ammonium).
This is not really a method of removing ammonia, but it is important to note that fish in higher pH and higher temperatures are at higher risk of ammonia poisoning that those kept at lower pH or at lower temperatures.
This method is not universal as one cannot simply change pH or temperature for all fish to suit this.
There needs care on adjusting acid-loving fish to even lower pH in that the sustainable biological activity of removing ammonia (see below) will be reduced or halted.

6. Aerobic Biological Action by Nitrosofying bacteria
This is part of the nitrogen cycle that fish-keepers should get working in their tanks.
It takes a short while (a few days to a few weeks) for a colony of bacteria to cope with the normal amounts of ammonia produced within a tank.
Oxygen and ammonia/ammonium are required for the colony to grow.
An original seeding of bacteria in the tank is required: that will develop naturally with time, but can be speeded up by adding suitable colonies of bacteria from either an off-the-shelf product or from using mature water or bacteria colonies from another healthy fish-tank.
It is sustainable, yet changes in water quality can halt the activity.
Efficiency can vary from very poor to very efficient.


7. Anaerobic Oxidation of ammonia by bacteria
The bacteria involved with anaerobic oxidation of ammonia to produce nitrogen gas take a long time (many months to years) to get going in a tank.
This process is not the same as denitrification. Denitrification is the reduction of Nitrates to Nitrogen gas whereas this process is the direct oxidation of ammonia to nitrogen.
Requires anaerobic conditions.
For some reason, this process is rarely seen in fish-keeping communication; it is not a rare process.

8. Direct Assimilation by organisms for use as a nitrogen source in growth.
Some organisms will use ammonia directly for use in their nitrogenous biological molecules.

ian

Thx Ian

They also appear to be in order of poularity too.
Is there a conclusion to these methods ?

JustinK wrote:

They also appear to be in order of poularity too.
Is there a conclusion to these methods ?

That's what I was hoping to be asked.

There is a conclusion, or several conclusions.

1. When starting to stock a tank be prepared for a quick succession of partial water changes and increased aeration.

2. Aim towards maturing the tank completely but some parts of complete maturation need not be attained so long as the Aerobic oxidation of ammonia to nitrite to nitrate can be done in the tank and sufficiently for the tank and its occupants.

3. pH and temperature are important measurements along with ammonia measurements.

4. It is cheap enough to have emergency aids at hand (eg Polyfilter), and should be at hand as anything can go wrong with any tank.

5. Understand that ammonia is a deadly toxin. You do not need to understand the science behind all of this, but ultimately if something goes wrong then the heavy science will kick in when anyone starts asking questions on a tank disaster.

Point 2 is THE important point here.

ian