Where does BBA come from? I've heard that it is introduced as spores in water when buying new fish/new plants?

Is it also in the air?

If it can only be introduced, I guess that would mean that if a tank was set up that didn't contain any spores, it wouldn't matter how out balance the tank was, it would show other forms of algae but never BBA?

I'd say it's impossible to avoid virtually any species through spore removal/avoidance.

The real issue is to address prevention of GERMINATION of the spores.
Some are air born(most FW species).

Folks have been thinking they can outwit algae via this way for decades.
Never once has it worked.

Some seem to think they will be the "first".
And they get it anyway.

You are talking about doing sterile technique, which is possible, but very very impractical and virtually impossible over the lifetime of most aquariums(say 10-20 years).

It's far far easier and better for the plant to focus on other control points, like the plants themselves Then you do not have an algae issue and the plants grow very well, which is the goal here.


Regards,
Tom Barr