Some tips from mr.wilson:
QT & HT is a matter of quality rather than quantity. You need enough room for tangs and those impulse buys, but less is more in most cases as water changes and medications go farther. You don't have to follow all of my suggestions, just use it as a guideline. Due to the scope of the post, I have excluded medication dosage and handling practices.
1) A lid to keep in jumpers (glass or egg-crate). Wrasse and gobies are far more likely to jump in a small empty tank. PVC hiding places will also help.
2) A heater. much more important than in display tank. Unlike freshwater, marine ich is cued by temperature increases, rather than decreases. A heater will make a consistent temp.
3) Indirect, diffused light. Try to keep a ten hour photo-period to reduce stress. Many antibiotics are photo-degradable, so direct light should be avoided. Sudden light flashes as experienced with fluorescents will cause fish to jump and go into shock.
4) An artificial bio-filter. This can be a bio-wheel or canister filter that is normally run on the display tank to keep it cycled. It is too small to adversely affect the display tank. Remember not to use carbon as it will remove medications. Alternatively, you could just store the filter media in the display tanks sump to keep the bacteria viable.
5) Have plastic cups to catch and move fish. Unlike freshwater fish, marine fish haven't adapted to breathing atmospheric air even for a brief period of time. Most secondary bacterial infections are caused by fish net abrasions.
6) An ultraviolet (UV) sterilizer. They cost a couple hundred dollars but they will pay themselves off after they save a few fish. The bulb will last a long time as it will only be used while you have fish in the QT. You could borrow a UV sterilizer from the display tank without causing too much trouble. UV sterilization should be discontinued if you are using antibiotics.
7) Have medications on hand so they are there when you need them. I use chloramphenical and neomycin together as a prophylactic treatment for bacterial infections. I use coppersafe or cupramine with quinacrine hydrochloride (quinine) for parasites. Malachite green, formalin, and nitrofurazone are also good to have around, but they adversely affect water quality and should be used only when needed. Rifampin or isoniazid should also be used prophylactically to prevent marine tuberculosis (mycobacterium) which is very common in new arrivals. Dewormers such as piperazine should be given in the food. None of these preventative treatments greatly affect water quality and will not cause significant mutation (resistant strains) of pathogens. Quarantine for 21 days minimum to break the parasite life cycle.
8) Keep a low salinity of 1.013 to 1.017. Stressed marine fish can dehydrate when placed in standard salinity water (1.023+). They don't have a healthy slime coat to regulate osmotic pressure and have to work a lot harder to pump salts out of their bodies. A lower salinity will also slow fish metabolism and kill parasites. Ammonia is also less toxic at a lower salinity as well. Fish adapt well to being moved to water with a lower salinity. They adapt poorly to moves to higher salinity.
9) Keep mixed saltwater on hand. Use display tank water for QT tank water changes. Add new saltwater to display. This will remove nitrogen compounds from QT and supply fresh pro-biotics (micro-organisms that will out-compete with pathogens). Following this practice assures that the quarantined fish will be acclimated to display tank water at all times. Remember to top-off meds and adjust salinity. One week before moving the QT fish to the display tank, you can start adding more display tank water to slowly raise the salinity to avoid osmotic shock.
10) Use large pvc pipe segments for hiding places. Paint back and side walls to provide additional shelter.
11) If a disease breaks out, sterilize the tank with bleach before re-use.
12) have a bucket of aerated freshwater of equal temperature handy for freshwater dips. Don't use RO/DI water for freshwater dips. Tap-water has a closer PH and general hardness. The chlorine is also medicinal as an oxidant.
13) Make sure your medications are compatible. Formalin and nitrofurazone don't mix for example. EM (erythromycin) doesn't mix with calcium salts, and EM and nitrofurazone don't mix well either.
14) Medications have a treatment and prophylactic dose. For example, copper should be 15 ppm for QT and 30 ppm for HT (hospital tank).
15) Use a bare bottom, so you can wipe the inside surfaces daily (in HT). This will dislodge and kill parasites in the tomont, trophont, and dinospore stages of their life cycle. A diatom filter will remove these 25-50 micron parasites. You also want to avoid calcareous media as it binds copper.
16) Medicating the food will help treat the fish for internal bacterial, parasite, and fungal infections without adversely affecting water quality. Short freshwater dips and medicated saltwater baths will also help.
17) A flashlight is a very effective tool while evaluating fish health. It casts a shadow if cysts are present. This gives you a good head start for treatment.
18) A sharp, new, single edged razor blade can be used to trim away lymphocystis on the margins of fins.
19) Use a dedicated net for the QT and HT. You can use potassium permanganate or methylene blue as a net disinfectant. Segregate any thermometers, towels, feeding devices, and wash your hands to avoid spreading pathogens to the display tank.
20) A good camera will help you take pictures to submit for help in diagnosis and treatment.
21) Have a smaller, second HT tank for very sick fish. This helps eliminate fish to fish disease transmission as the healthy fish pick on the sick ones.
