In short, the type of food and amount of food can and does determine the micro fauna diversity in the tank. Unprocessed food =more pathogens,
high protein food = more pathogens, more decomposition = low oxygen, more pathogens.
I won't even mention the effect on bio-load when you overfeed. But underfeeding is also not a solution as it leads to malnutrition.
In biofloc systems they use certain food types, mainly low in protein and high in carbs as an indirect pathogenic bacteria inhibitor via the establishment of friendly heterotrophic oxygen water column decomposition. Those bacteria rely on carbs, literally, as in sugar carbs and they out compete the pathogenic bacteria if maintained correctly. In those systems they provide high constant flow to keep the solids suspended in the water to prevent anaerobic decomposition.
Either way, food is going to get processed one way or another, whether first broken down by fish, then by bacteria or direct bacterial decomposition. In nature, there is a chain of events, fish eat fish, food going through fish, then shredders such as shrimp and snails, then smaller shredders, then bacteria decomposition, both aerobic and anaerobic. The longer the chain, the better.
In general, the more natural the tank setup, including having plants which create conditions for non-pathogenic microbial diversity, and also diversity of other critters as shredders, be it worms, shrimp, snails, etc.. the more robust the tank conditions are for the fish.
In a bare bottom tanks with large fish fed high protein food that won't be exactly the case so take out that siphon...A filter only, bare bottom tank is the least stable tank setup and prone to issues.
high protein food = more pathogens, more decomposition = low oxygen, more pathogens.
I won't even mention the effect on bio-load when you overfeed. But underfeeding is also not a solution as it leads to malnutrition.
In biofloc systems they use certain food types, mainly low in protein and high in carbs as an indirect pathogenic bacteria inhibitor via the establishment of friendly heterotrophic oxygen water column decomposition. Those bacteria rely on carbs, literally, as in sugar carbs and they out compete the pathogenic bacteria if maintained correctly. In those systems they provide high constant flow to keep the solids suspended in the water to prevent anaerobic decomposition.
Either way, food is going to get processed one way or another, whether first broken down by fish, then by bacteria or direct bacterial decomposition. In nature, there is a chain of events, fish eat fish, food going through fish, then shredders such as shrimp and snails, then smaller shredders, then bacteria decomposition, both aerobic and anaerobic. The longer the chain, the better.
In general, the more natural the tank setup, including having plants which create conditions for non-pathogenic microbial diversity, and also diversity of other critters as shredders, be it worms, shrimp, snails, etc.. the more robust the tank conditions are for the fish.
In a bare bottom tanks with large fish fed high protein food that won't be exactly the case so take out that siphon...A filter only, bare bottom tank is the least stable tank setup and prone to issues.