Ok... so he was doing really great... then did water change yesterday using tap water (had only been using bottled water since the last time)... woke up this morning and now he's floating again... he's totally hanging out of his shell, I thought he had died but he moved and was quick to close the shell door... so
a) the betta could have had a scuffle with him last night...
B) I did introduce new plants into the tank as he nommed on all the other ones maybe they made him sick.
c) Something in the tap water is getting to him... but my water levels are OK based on my testing strips.
So as much as I don't want to spend the $$$ on pet store goldfish water or bottled water... it may be the only thing that will help since there must be something in the local tap water that the betta can tolerate but the snail cannot and the nitrate remover/bacteria drops cannot neutralize.
I also noticed air bubbles were coming out of the shell... which made me think trapped air.
I added more nitrate remover drops to the tank. Hope things turn around again... but I'll do another water change with the bottled water and hope that it helps.