Thoughts on unnexplained (and very sad) die-off

[kien]

Sorry to hear if your loss. The hobby is hard enough as it is but to loose your tank inhabitants like that is a real kick to the nads :-(. Been there.. :-(

When you treated your tank with prazi pro did you turn off your skimmer like the bottle suggests? If I recall correctly the instructions say that you should turn off your skimmer. This is likely due to the fact that your skimmer could skim out the meds making it less effective. HOWEVER, I personally would not recommend doing this as turning off your skimmer for a period of time can dramatically reduce the oxygen in your tank. Mind you, if you don't have a skimmer then this is a non issue.

My recommendation when using meds with a skimmer is always to take off the skimmer cup and let it overflow into your sump during the treatment period. Assuming you have a sump of course.