I don't think FW BioSpira is around. SW might be, but neither are/were products I'd want to use so didn't really follow them.
I am, and yes, that's the one. I was thinking of Dr tim's too, but never used it so not sure how well it works(and couldn't recall that name either).
Unless they die, you're only going to end up with a bacteria colony that can handle the bioload of a couple of ghost shrimp... perfect if that's how you
You may still be living in the early-mid 2000s in which case you're likely thinking of BioSpira,
these days you might want to look at Dr
The necessity for larger quantity and more frequent water changes is largely dependent on the relative size of the discus. Small young discus, say 1"