17 gallon as a QT

[Lemeshianos]

I have a 17 gallon tank that is used as a freshwater tank.
I plan on giving the animals and decoration away and use it as my QT for saltwater. The only chemicals added in there was dechlorinator and black water extract(for pH).
There was also ich treatment twice if I can remember correctly, but I don't think it contained any copper since I've had invertebrates later on and they are fine.

I am concerned whether its ok to use that one since it has a filter, heater etc.
The size could be an issue since I plan on getting a pair of clown and a yellow tang (I know that tangs requires a 75gal +). My main is 115 gallons.
Is the 17 gallon too small for a QT? Should I get a bigger QT or should I get the yellow tang as my first fish and later on get the clownfish?

 

[Tswifty]

What are the dimensions on the QT tank, and how large of a tang are you considering?

Generally I like to use a large Quarrantine Tanks, and have a small 15g Hospital Tank on hand in case any of the fish would need to be isolated for treatment.

The clownfish would definitely be fine in a QT setup of that size. However, a small QT tank may do more harm than good when it comes to tangs. As they become stressed easily.