So I ran out of the stuff I have been using (Tetra BettaSafe) so I picked up Prime because I figured that's the best stuff. Did a water change on all three tanks this morning, adding the Prime. Withing hours all of my boys were lethargic and laying on the bottoms of their tanks.
Ran to Petsmart and bought another brand and did water changes again. They seem better but not back to normal.
The expiration dat is nex is 2013, I calculated the Prime and used a new syringe to add it. (I'm a medical assistant I calculate dosages). I acclimated the fish like usual, I just don't know what else it could have been.
Just wanted to put this out there in case anyone else has seen this happen.