Masha
Aquarium Advice FINatic
The more I learn about it, the more it seems that fish keeping is really bacteria keeping
I found this article (I think it was a link from fishfur? My firewall threw a false positive, calling it "harmful" but when I queried it, it turns out that the page is quite safe) Bacteria in the Freshwater Aquarium
Here is something I found very interesting - quote from the article (bolding is mine):
These species of heterotrophic bacteria break down dead organic matter like fish waste, dead fish or plant matter, uneaten fish food, dead bacteria, etc. Some are aerobic, but many species are facultative anaerobes, able to live with or without oxygen.
...
These bacteria have only one requirement to appear and live: organics. They compete with autotrophic bacteria for both oxygen and surface area; studies show that even in relatively clean environments, they occupy more than 50% of the available surface area. And given that they can reproduce within 15-60 minutes—compare this to the 12-32 hours required by nitrifying bacteria—you can see how easily these heterotrophic bacteria can overwhelm the system. In a filter, if sludge is allowed to increase, heterotrophic bacteria will multiply so fast they actually smother and kill the autotrophic nitrifying bacteria.
And this too:
The greatest population of bacteria in a healthy balanced aquarium occurs in the substrate, not the filter. The floc or humic compost that collects in the substrate is the host for the biofilms; this is why the substrate in planted tanks should never be disturbed, and many aquarists apply this to non-planted tanks as well.
In very general terms, aerobic nitrification takes place in the top 1-2 inches of the substrate; anaerobic de-nitrification takes place approximately 2-4 inches down, and anaerobic bacteria producing hydrogen sulfide occurs in substrates deeper than 3-4 inches. In all three cases, it will be deeper in coarse substrates (like pea gravel) and more shallow in finer substrates such as sand. These generalities will also vary with the presence of live plant roots and substrate “diggers” such as snails and worms, since these factors result in more oxygen being made available in the substrate, reducing anaerobic bacteria activity. An oxygen level in the substrate of as little as 1 ppm promotes nitrogen reduction rather than sulfur reduction (hydrogen sulfide). [6]
Maintaining a substrate of fine gravel or sand no deeper than 4 inches, having live plants rooted in the substrate, and keeping Malaysian Livebearing snails are the best and safest methods of providing a healthy biological system for aerobic and denitrifying anaerobic bacteria.
I did not know that the sludge in your filter could be from heterotrophic bacteria? I always thought that you had to rinse it simply to keep the water-flow going, so the BB gets enough oxygen?
And this also explains why you should be careful of doing gravel vacs? Cleaning the gravel gets rid of the good BB?
Also that heaping up your substrate deeper than 4 inches might be a bad idea?
I really want to get some Malaysian trumpet snails now
I found this article (I think it was a link from fishfur? My firewall threw a false positive, calling it "harmful" but when I queried it, it turns out that the page is quite safe) Bacteria in the Freshwater Aquarium
Here is something I found very interesting - quote from the article (bolding is mine):
These species of heterotrophic bacteria break down dead organic matter like fish waste, dead fish or plant matter, uneaten fish food, dead bacteria, etc. Some are aerobic, but many species are facultative anaerobes, able to live with or without oxygen.
...
These bacteria have only one requirement to appear and live: organics. They compete with autotrophic bacteria for both oxygen and surface area; studies show that even in relatively clean environments, they occupy more than 50% of the available surface area. And given that they can reproduce within 15-60 minutes—compare this to the 12-32 hours required by nitrifying bacteria—you can see how easily these heterotrophic bacteria can overwhelm the system. In a filter, if sludge is allowed to increase, heterotrophic bacteria will multiply so fast they actually smother and kill the autotrophic nitrifying bacteria.
And this too:
The greatest population of bacteria in a healthy balanced aquarium occurs in the substrate, not the filter. The floc or humic compost that collects in the substrate is the host for the biofilms; this is why the substrate in planted tanks should never be disturbed, and many aquarists apply this to non-planted tanks as well.
In very general terms, aerobic nitrification takes place in the top 1-2 inches of the substrate; anaerobic de-nitrification takes place approximately 2-4 inches down, and anaerobic bacteria producing hydrogen sulfide occurs in substrates deeper than 3-4 inches. In all three cases, it will be deeper in coarse substrates (like pea gravel) and more shallow in finer substrates such as sand. These generalities will also vary with the presence of live plant roots and substrate “diggers” such as snails and worms, since these factors result in more oxygen being made available in the substrate, reducing anaerobic bacteria activity. An oxygen level in the substrate of as little as 1 ppm promotes nitrogen reduction rather than sulfur reduction (hydrogen sulfide). [6]
Maintaining a substrate of fine gravel or sand no deeper than 4 inches, having live plants rooted in the substrate, and keeping Malaysian Livebearing snails are the best and safest methods of providing a healthy biological system for aerobic and denitrifying anaerobic bacteria.
I did not know that the sludge in your filter could be from heterotrophic bacteria? I always thought that you had to rinse it simply to keep the water-flow going, so the BB gets enough oxygen?
And this also explains why you should be careful of doing gravel vacs? Cleaning the gravel gets rid of the good BB?
Also that heaping up your substrate deeper than 4 inches might be a bad idea?
I really want to get some Malaysian trumpet snails now