I wouldn't suggest EVERY adding any treatment chemicals to a reef tank. Most will cause problems at minimum...and kill all your inverts and corals at the worst extreme. This is just my opinion, but if you can't afford a QT tank, you shouldn't get your fish yet, especially wild caught. That being said, do some research into freshwater dips.
You can set up a QT tank very cheap. A 10 gallon tank with an inexpensive small HOB power filter and a couple pieces of PVC fittings for the fish to hide in is all you really need. I don't even have a heater in mine..although I don't have heaters in any of my tanks. Not needed in my house. Oh wait, yes I do have a small heater in my QT tank...lol.
Put it this way, you can set up a QT tank for under $50.00. You'll pay a lot more than that if you end up killing off your entire tank by not using QT. Most people who don't follow this advice to begin with...soon learn the hard way. I know I did. In fact, my hard lesson was taught to me the exact same route you're going. 2 Wild Percs. Soon afterwards, everything in my tank was dead and I had to do an 8 week fishless cycle of the tank AND a hyposalinity treatment. Lost almost everything.