The Medicine Cabinet

Here's a brief overview of what to stock in your fish medicine cabinet and how to use it, should your fish become sick:

Cupramine (copper medicine)
What it Treats:
Ectoparasites like Marine Ich (Cryptocaryon irritans), Marine Velvet (Amyloodinium ocellatum), and Gill Flukes.
How To Use It:
Use 1 ml (stock is 10,000 mg/l) per 10.5 gallons for final concentration of 0.5 mg/l
Add once and leave for 14 days
Use a test kit (from same manufacturer) to measure copper levels
Therapeutic at 0.2 mg/l and toxic at 0.8 mg/l
Advantages:
Cupramine is safer than other copper medications (copper sulfate, chloride, citrate). It's less toxic to fish and also does not precipitate out of solution. There's no risk of fluctuating copper levels. In addition, it's more effective than chelated copper meds.
Notes:
Removable with carbon (this is why you always remove your carbon filter before adding meds; to remove meds at end of treatment, just put the filter back)
Do not add more unless test copper concentration with test kit (from same manufacturer)
Do not use with any other medications (reducing agents, like formalin, increase copper concentrations to toxic levels)
Links:
http://www.seachem.com/Products/product_pages/Cupramine.html

Formalin (37% formaldehyde)
What it Treats:
Parasitic infections, particularly hard-to-treat Brooklynella (Clownfish Disease)
How To Use It:
Use as a bath
1 ml of 37% solution per gallon water
Make sure temp below 80, pH 8.0-8.4, and vigorous aeration with airpump included.
Treat 45 minutes 1x/day for 3-5 days
Notes:
Formalin is pretty toxic (it's a carcinogen; wear gloves). In addition, it sucks oxygen out of the water. Temperature and pH affect formalin toxicity (above 80 degrees, it takes out even more oxygen). Be sure to use vigorous aeration. Methylene blue is often used in conjunction (it helps the fish get more oxygen).
Links:
http://www.reefland.com/forum/marine-fish-care-health-disease-treatment/25290-formalin-treatment-marine-fishes.html
http://saltaquarium.about.com/od/ichparasiticdiseases/ht/treatbrooklynel.htm

Methylene Blue
What it Treats:
Fungus and some external protozoans like ich
How To Use It:
add 1 tsp of 2.3% solution per every 10 gallons (3 ppm final concentration) in QT for 3-5 days; only one application is needed
use water change plus carbon filter to eliminate methylene blue at end of treatment
Notes:
Methylene Blue is an oxygen transporter for fish, increasing ease of respiration (great in conjunction with formalin since formalin compromises oxygen)
Can be used in conjunction with some medications (check manufacturer's instructions carefully)
Not effective bacterial infections, flukes, or brookynella
Removed by AmQuel at high concentrations
Links:
http://www.novalek.com/kordon/methylene_blue/index.htm

Malachite Green
What it Treats:
Treats ich, fungus, and other external parasites (gill flukes)
How To Use It:
use 1 tsp per 10 gallons
as a bath: 1-2 mg/l for 10 min or 0.5 mg/l for 1 hr
Notes:
Often used in conjunction with formalin
This is toxic stuff! Use caution.

De-Wormer (Praziquantel)
What it Treats:
Tapeworms, roundworms and other internal parasites
How To Use It:
Can use as a bath (1 tsp per gallon) in QT for 5-7 days
Often mixed with food
Links:
http://www.reefsanctuary.com/forums/fish-diseases-treatments/37765-de-worming-marine-fish-super-pooper-snooper.html


Antibiotics
What it Treats:
Bacterial infections (pop-eye, bladder infection, fin rot, etc.)
How To Use It:
Add to QT water per manufacturer's instructions and/or food
Notes:
Start with broad spectrum antibiotics, ones that kill both gram-negative and positive bacteria.
These include:
Neomycin
Chloramphenicol
Nitrofurazone based products
Skin absorbed kanamycin sulfate based antibiotics (Kanacyn/K-Mycin)
Try a product like Spectrogram (Aquatronics) or Maracyn One, followed by Marcyn Two.
Other Antibiotics:
Tetracycline
Sulfathiazole
Metronizazole (treats protozoan and anaerobic bacterial infections in fish as well as dinoflagellate infections)

Note: Many of these chemicals are toxic to humans. Please wear gloves and handle carefully.

Links:
http://www.reefland.com/forum/marine-fish-care-health-disease-treatment/18893-stocking-marine-fish-medicine-cabinet.html
https://www.fosterandsmithaquatics.com/pic/article.cfm?N=2004&aid=1338