Thank you, thank you. I will look to my local stores first and also search out online vendors. Question: fellow reefer Formulator mentioned the possibility of something toxic got into my tank. Would a Triton ICP test be something to consider? Besides a few frags I recently added to the tank, I did start dosing Kalkwasser to elevate my pH. Maybe I accidentally made it too concentrated. But that seems unlikely given my water parameters are decent. One more thing worth mentioning is that right before the fish all died, I performed a 20% water change using a brand new batch of Tropic Marin Pro Reef. Could I have a contaminated batch? Then there's Velvet, which Jay mentioned. It's frustrating not knowing the cause. I even checked the tank components for errant electrical current.
Lastly, I do not have a quarantine tank. It would probably be another big expense, but it certainly would be prudent and handy.
Thanks again for all the help I've received.