Hey all, after being gone and out of the hobby for awhile, and coming back, I see a lot of posts from newer members about treating diseases and setting up hospital and quarintine tanks. After recently suffering a bout of what I am calling "fish aids" (nearly lost whole tank, no obvious signs of disease, good water quality) I set up my tusty HT/QT system and thought I would share. It's currently housing a maroon clown that got beat to hell after a failed pairing. First, what is a hospital or quarintine tank, and is there a difference? Well, there can be depending on what you want. A quarantine tank is normally considered exclusive to new fish purchased, to house and observe for disease and eating habits, before adding to your main system. A hospital tank is used for treating fish, whether new or established, with medications that may normally harm or even kill other tank inhabitants, such as coral, shrimp, or even the bacterial load of an established tank. I use mine for both, with newcomers being treated for disease, whether they show signs or not. My system is simple, and may or may not work for you depending on your needs. Mine is a simple ten gallon, but a good rule is that yours should be large enough to house your largest fish for one month. A hospital tank requires a good deal of maintenance while treating, so keep in mind how much you want to be working with as well. Of course, larger is always better. Nest is equipment, and again it can be pretty simple. First and foremost, a heater that can maintain a good temp. A lot of experts point out a higher temp can help with ich treatment, so keep that in mind. Second is something for a little flow. On mine, I use just a piggy back filter, which helps also with large pieces of detritus and uneaten food, but a powerhead is fine also, or of course both. Keep in mind if your using a filter, avoid using carbon in a hospital tank, as it will absorb medications making it more difficult to keep them at appropriate levels. I also run an airstone in mine, giving a little extra movement and extra oxygen to a sick fish. I run mine bare bottomed, but substrate can be used. Technically, mine is not cycles, but if your going for quarintine only, you may cycle the tank. Some may cycle a hospital tank, but keep in mind, many medications and treatments may destroy the bacterial load, making cycling pointless. The next and last thing on the list is a place where the fish can hide and feel safe. I just use a few pieces of PVC and a fake aquarium plant, but your imagination and wallet are the limit here. But at minimum you want a few holes that your largest fish can hide and feel safe in. What about lights? You really do not need any. The dimmer lighting will help calm the fish, and the ambient room lighting is enough to tell them when its day or night. I do not run lights on mine, but make sure the room is at least bright enough to easily see the fish for visual inspection. And what about water parameters? You should be checking these very often, specially if your not going cycled. Also, you need test kits for the appropriate medications you are using, like copper. And you need to make sure you have the appropriate type of copper test kit. Commonly, copper medications come in two forms, chelated and ionized, and you need the correct test kit for each. If uncycled, count on frequent water changes. I need to do mine about every three days. It can seem very daunting at first to have one of these systems running, but it really doesnt have to be. I threw mine together for about $50 total, and it has served me well for many years. And the new hobbyist needs to realize this is money well spent. Just one infected fish can bring down a system, and for less then the cost of one flame angel or tang, you can gaurd against it. Do a simple inventory of all your fish, and you'll quickly realize how much losing them will cost you.