So, you have figured out by the white spots and scratching that your fish have ich. Now what? Depending on the fish there are different treatments available including Copper, Quick Cure, Kick Ich, and Kent RxP to name a few. There are also other methods besides using chemicals like increasing the temperature and decreasing specific gravity. To figure out what direction to start treating it all depends on what is in the tank and what the water quality is. If the water quality is poor (high levels of ammonia or nitrite) then medications are pretty much useless and will cause more harm than good.
For tetras and other scaleless fish such as catfish, loaches, elephant nose, I usually recommend increasing the temperature and use a product called Quick Cure. The active ingredients in quick cure are malachite green and formalin. Make sure you follow the directions and only use a half dose. When at all possible this treatment should be added to a quarantine tank only.
For other community fish such as mollies, platys, swordtails, rainbows, gouramis, and cichlids I also recommend using quick cure. You can do the full dose with these fish. Copper can also be used but must be used with extreme caution. Copper must be monitored because there is a fine line between killing the parasite and killing the fish being treated. These medications should only be used in a quarantine tank. Medications will kill plants and inverts such as snails and shrimp.
For saltwater fish, again, Quick Cure is my medication of choice if used in a quarantine tank with no inverts. Copper can also be used but some fish are very sensitive to it. Increasing the temperature a few degrees and decreasing the specific gravity to 1.019 over the period of a few days can help speed up the life cycle making the medication more effective.
For a saltwater reef tank or a fish only tank with inverts you can give Kick Ich a try. The active ingredient is 5-nitroimidazoles. This should only be done as a last resort if the fish cannot be taken out of the main tank. I have gotten back mixed results with using this product though. Some people say it works great while others say it did nothing. I am assuming that if it is caught early enough and the fish only have a few spots then the medication is effective and is enough to boost the fish’s immune system enough to fight it off and make a full recovery. However, if the fish is covered with ich the medication is just not strong enough to save the fish. Another product out there is Kent RxP. The active ingredients in this product are Deionized water, natural plant extracts, pepper, stabilized vitamin c, stabilizers.
To prevent ich from entering your main tank it is advised to quarantine all new fish for at least a month. If in that period of time your fish develops some kind of illness it should be treated accordingly and the time clock should start over. Once the fish has been symptom free for a month you can be fairly sure you are not going to introduce a disease into your display tank.
Feel free to email us with any ich questions you may have!