True nitrifying bacteria are strictly aerobic autotrophs.

They can only use nitrogen from inorganic sources such as ammonia and nitrite. Nitrosomonas (ammonia-oxidizers) and Nitrobacter (nitrite-oxidizers) are the most common.

Heterotrophic bacteria are generally considered to be organic sludge degraders.

They are mostly from the genera Bacillus and Pseudomonas. Most of these are facultative anaerobes; meaning they can function with or without oxygen. They will do completely different functions depending on the level of dissolved oxygen present.

Heterotrophic “nitrifiers” prefer to obtain their nitrogen from organic sources such as decomposing organic debris.

Those that can convert ammonia do so only when an organic nitrogen source is not available. This is unlikely to happen in an aquarium or pond where fish are present. The explosion of “nitrifying” bacteria products in the industry is due to research that some heterotrophs can use ammonia-nitrogen. However, this is under ideal laboratory conditions

Heterotrophic “nitrifiers” generally cannot utilize nitrites.

Only a few species are capable of reducing nitrite to free nitrogen, but, under strictly anaerobic conditions.

Scientific studies indicate that, depending on species, between one thousand to one million heterotrophic bacteria cells are required to perform the same ammonia conversion rate as one Nitrosomonas bacteria cell.

FritzZyme® 7 has a cell count of 30 million bacteria per ounce, 50% of which is Nitrosomonas and 50% Nitrobacter.

To obtain the same ammonia conversion rate, a competitive product composed of heterotrophic “nitrifiers” would require the addition of 15 trillion bacteria. This would probably require several gallons of another product. No quantity of heterotrophic “nitrifiers” would reduce the generated nitrites.

Heterotrophic “nitrifiers” can also operate in the reverse direction

...that is they can convert nitrate to nitrite or ammonia, especially during times of low dissolved oxygen levels. In a pond, this could potentially happen during the hours before sunrise when DO levels are at their lowest.

There are no dry forms of any bacterial product that can contain viable Nitrosomonas and Nitrobacter cells.

Unlike heterotrophs, they cannot form spores so they cannot survive any type of drying or freeze-drying process.

Independent Studies

California State, Texas A&M Corpus Christi, University of Nevada Las Vegas


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