Yes. Biodiversity generally leads to interactions that makes an ecosystem more resilient.1) Is there merit to this claim or is a diverse set of bacteria actually a good thing in the long run?
Theoretically, after nitrifiers are established since we kinda want them to have less competition. But in practice, especially from personal experience, it does not quite matter that much. So imo, chuck whatever you want in whenever. ^_^2) When should one add live sand if there is a bacteria Thunderdome competition?