A quarantine tank doesn't have to be expensive, but owning and using one will save you money and heartache. Your healthy fish and vibrant corals look great as you introduce that new item you just picked up from a buddy that you trust or your favorite fish store. Within a short period of time, you discover you've unleashed something evil into the system. It can take months to fix the problem, and often this will be costly. Or you can set up a quarantine tank and play it safe.
My quarantine tank (QT) is a simple box of water. Made of acrylic, it holds about 12g of water. I use a small 50w heater, a LED light, and a Vortech MP10 for flow. Some dedicated live rock and some PVC fittings complete the system.
PVC fittings gives the fish a place to retreat to if aggression takes place. Daily water changes keep the water parameters in check, taking water from my reef to refill the QT, and then adding new saltwater to my reef.