Good does not always equate nitrifying..write up (beginner focused)

[reef.keeper]

All nitrifying bacteria is good, but not all good bacteria nitrify. There is a long list of
bacteria that are beneficial and thrive in our reef tanks. Some live in the water, some on surfaces. Some of these bacteria nitrify, but most do not. These non-nitrifying beneficial bacteria consume waste, phosphates (then consumed by corals), dissolved organics, and even act as defense against pathogenic bacteria. This hobby has a problem where newer hobbyist throw around the term "good" bacteria when referring to the nitrogen cycle. This of course carries over into other conversations where this is simply nonsensical. For example. when UV is discussed, people will bring up that it is killing good bacteria, which it is. However, these people are not referring to nitrifying bacteria. Then comes in the "good bacteria mean nitrifying crowd" and begins to argue that nitrifying bacteria doesn't live in the water, which it doesn't. Hobbyists then have convoluted arguments about nothing when each side is factually correct but neither realizes the argument is over nothing but a misplaced word leading to a zero-sum game where the only thing at the end of it is irritation and false ideas.
When discussing bacteria, especially on the internet, one needs to be specific. Realize that, when someone says "good" they may or may not be talking about nitrification. Make no assumptions and ask for clarification to avoid confusion and the spread of incorrect information. I have talked to many people with crashed tanks who started their tank with old tank water because of its "good" bacteria. Only to find out it contains little to no nitrifying bacteria. This bad word play is sprinkled all throughout the hobby. Proceed with caution and precise word choices.

 

[Subsea]

Good introduction.

The second part to the conversation, is that the photosynthetic organisms will compete with the bacteria for nutrients. Meaning that nitrification bacteria are not even relevant to nutrient management in a mature reef tank.

 

[Randy Holmes-Farley]

All nitrifying bacteria is good,

Well, I disagree with the premise that nitrifying bacteria are always good. In many established tanks (those with steady or falling nitrate), they just rob corals of ammonia, leaving them to make do with less desirable nitrate. :)

I personally think many tanks would be better off without them.

This is not an idle thought. Many folks repeatedly dose nitrifiers to established tanks, which I think may be detrimental despite the hobby mantra that nitrifiers are "good".

 

[Subsea]

Well, I disagree with the premise that nitrifying bacteria are always good. In many established tanks (those with steady or falling nitrate), they just rob corals of ammonia, leaving them to make do with less desirable nitrate. :)

I personally think many tanks would be better off without them.

This is not an idle thought. Many folks repeatedly dose nitrifiers to established tanks, which I think may be detrimental despite the hobby mantra that nitrifiers are "good".

I will second that after initial nitrification bacteria cycle that dosing bacteria in a bottle is not only unproductive, it is detrimental to stabilization in a reef tank.
One of the reasons that I am skimmerless is because it skews bacteria diversity and because my focus is the microbial food web, I choose not to use foam fractionators in my reef tanks.