I have been out of the hobby for almost a decade, and due to my background tend to review the scientific literature on topics that interest me. I was surprised to see some very compelling research on the topic of freshwater aquarium biofilters in the last 10 years, and very little discussion about it in aquarium forums I used to be part of. I am not totally sure why that is...
In any case - here are some tentative findings that I have tried to extract from the literature.
1) The long-term primary ammonia-oxidizing component of biofilters is clearly NOT biosomonas and similar bacteria (AOB) as previously thought. Rather, it is ammonia-oxidizing archaea species (AOA). Note that this is not true for marine tanks, only freshwater.
2) Biospira still seems to be one of the dominant forms of nitrite-oxidizing species, even in freshwater tanks.
These two things explain so much about difficulties with cycling and why bottled bacteria never seem to work quite as well as we would hope. Some of the literature on this is pretty dense unfortunately.
If you want to read any paper on this topic, there is a really interesting and much easier to understand thesis by a student at Waterloo:
Szabolcs, Natasha. "Ecology of Ammonia-oxidizing Archaea and Bacteria in Freshwater Biofilters."
https://uwspace.uwaterloo.ca/bitstream/ ... sAllowed=y
She basically shows that the most effective start to cycling a tank is one that includes introduction of AOA populations immediately, which none of the current "bacteria in a bottle" provide. AOB do seem to contribute to the initial process, but her experiments show much faster ammonia reduction with AOA inoculation.
See also (just a couple examples):
Bagchi, S. et. al. "Temporal and Spatial Stability of Ammonia-Oxidizing Archaea and Bacteria in Aquarium Biofilters."
https://dx.plos.org/10.1371/journal.pone.0113515
Sauder, L. et. al. "Aquarium Nitrification Revisited: Thaumarchaeota Are the Dominant Ammonia Oxidizers in Freshwater Aquarium Biofilters."
https://journals.plos.org/plosone/artic ... ne.0023281
My hypothesis is that SafeStart and similar products can "work" for fish-in cycles because nitrite is controlled and ammonia concentrations around, say, 1.0 ppm at normal ph ranges and temperatures are not actually that dangerous to fish over short time periods. The percentage of unionized ammonia (versus total ammonia) is very low until you get into high ph ranges (e.g. 8.0+). Those of us running high pH values therefore can't get away with such methods.
In any case - here are some tentative findings that I have tried to extract from the literature.
1) The long-term primary ammonia-oxidizing component of biofilters is clearly NOT biosomonas and similar bacteria (AOB) as previously thought. Rather, it is ammonia-oxidizing archaea species (AOA). Note that this is not true for marine tanks, only freshwater.
2) Biospira still seems to be one of the dominant forms of nitrite-oxidizing species, even in freshwater tanks.
These two things explain so much about difficulties with cycling and why bottled bacteria never seem to work quite as well as we would hope. Some of the literature on this is pretty dense unfortunately.
If you want to read any paper on this topic, there is a really interesting and much easier to understand thesis by a student at Waterloo:
Szabolcs, Natasha. "Ecology of Ammonia-oxidizing Archaea and Bacteria in Freshwater Biofilters."
https://uwspace.uwaterloo.ca/bitstream/ ... sAllowed=y
She basically shows that the most effective start to cycling a tank is one that includes introduction of AOA populations immediately, which none of the current "bacteria in a bottle" provide. AOB do seem to contribute to the initial process, but her experiments show much faster ammonia reduction with AOA inoculation.
See also (just a couple examples):
Bagchi, S. et. al. "Temporal and Spatial Stability of Ammonia-Oxidizing Archaea and Bacteria in Aquarium Biofilters."
https://dx.plos.org/10.1371/journal.pone.0113515
Sauder, L. et. al. "Aquarium Nitrification Revisited: Thaumarchaeota Are the Dominant Ammonia Oxidizers in Freshwater Aquarium Biofilters."
https://journals.plos.org/plosone/artic ... ne.0023281
My hypothesis is that SafeStart and similar products can "work" for fish-in cycles because nitrite is controlled and ammonia concentrations around, say, 1.0 ppm at normal ph ranges and temperatures are not actually that dangerous to fish over short time periods. The percentage of unionized ammonia (versus total ammonia) is very low until you get into high ph ranges (e.g. 8.0+). Those of us running high pH values therefore can't get away with such methods.