blue tang troubles

[luke33]

I'd guess it was a water quality issue as well or marine velvet as it takes fish quickly like you mentioned. Deep breathing, laying on there side...etc. I really doubt it was from adding a new skimmer.

 

[Ed Hahn]

i went to today all over the place and they were sold out of test kits. but i had her in a 100g but it was to big for my house so i moved everything to a 30g.... i know that it was a no no but i thought it would be fine for the time being guess not.. thanks everyone for the comments hopefully everything is ok now.

You just threw another log on the fire. You moved a fish from a larger environment to a smaller environment. Rapid switch in Ph burns fishes gill plates. They lay down on bottom looking like they ran a marathon.
So here is my guess. Fish sometimes will sometimes die due to handling. A Ph monitor and temperature monitor are your best friend when relocating fish.
Moving from a larger environment to smaller environment causes stress. When animals are stressed they create more amonia. You introduced a animal into a environment where other animals were already acclimated to PH.