Help My Salt Water Tank smell .??The $200 fish i brought look skinny and he keeps?

Question

I have a 47 gallon fish tank ..tall...I just changed 20% of the water like 8 days ago...The fish tank place said that my water was fine and i need to raise the ph...so i brought some ph buffer and a few fish... now my tank has this smelly order coming from it..I did turned the heater on for a while because the fish can get use to the water............???????? Need Help......Also one of the fish i brought look skinny and he keeps laying on the bottom of the tank.....Do Anyone know How I can Help him ...Is there any vitamins i can put in the water...for it...

Answer 1

get some water treatment and put you're fish in another tank for a few hours whilst the water treatment does its thing then place you're fish back into the water and the feed it generously hopefully that should do the trick  

:)