I use RODI water for all my water changes.... Out of all my tanks, this is the only one that has any ammonia show up when tested. Cleaned one of my Canister filters yesterday after 50% WC. This morning still showing 1.00, maybe a little more since the Colors are very close. I stopped adding Prime a week ago. I'm not going to do a WC today, but I will add Stability.
At this point, I'm really not sure why BB all died off, or what caused it.
Thanks for all the input.