If you could post a picture that would be good.
A QT is a good idea if they are sick. A 2.5 gallon is a very small size and you will probably have water quality issues. I would rec. a 10g for 2 clowns as if they do have ich and you are going to treat it, they would be in the QT for weeks.
You need a tank and an HOB filter of some sort, a heater if needed, a small powerhead rated for the tank you want to use and some sort of small PVC tube or something of the like so your fish can have somewhere to hide and 'feel safe'. No substrate as copper can be absorbed by it. And no live rocks as cooper will kill the lifeforms on it. Remember if you use copper that the tank will not be able to house any inverts beucase copper can leach into seals and inverts are very sensitive to it.
Hyposalinity is also an option. Just not both.
Your main tank needs to remian fishless so the parasite can die; they need a live host to complete their lifecycle.
Also be prepared to keep up on water quality. Ammonia can build up very fast. So you need to get test kits to moniter it.
I started a QT with 'old' tank water so that is acceptable.
Helpful?
HB
