Thanks everyone for the great help !!
just to update you all ...The 10g water swap has made a big improvement
on my tank . My PH is up at 8.3 and my regal tang is looking "ALOT" better tonight !!
I will be putting a kalk drip together so this doesn't happen again .
I told my wife she can look at the tank now .......she was upset this morning and thought we would loose the tang .
Thanks