It could be Brook or velvet. Your best bet would be to transfer the clowns, and all fish into the tank into a quarantine. Whether its ich or brook or velvet, the treatment is the same. Therapeutic levels of chloroquine phosphate for 30 days. And let the display tank sit fishless for a minimum of 78 days to kill off all traces of the parasite.
Chloroquine phosphate: Treats Ich (Cryptocaryon irritans), Marine Velvet Disease (Amyloodinium), Brooklynella hostilis & Uronema marinum.
How To Treat - Chloroquine phosphate (
CP) is a “new drug” that actually was widely used to control external protozoa in saltwater aquariums back in the 70s & 80s. It was even used in some aquarium medications sold at LFS. Nowadays CP requires a prescription to purchase legitimately, making it more difficult to obtain. Fast forward to today and thanks to the power of the Internet, CP has come roaring back! The biggest obstacle to overcome is obtaining
pharmaceutical grade 99% pure CP. I cannot stress the importance of this enough. Do not buy it from some guy on eBay or even an online vendor. The only way to be sure you are getting 99% pure CP is to get your vet (or an MD) to write a prescription which can then be filled by a compounding pharmacy.
CP is a “one and done” medication, meaning you dose once and that’s it. There are no test kits for CP, so it’s important that you dose accurately using a
digital scale. Also, don’t forget to dose any replacement water (from water changes, but not top-off) with CP. The dosage rates are as follows:
- Prophylactic treatment is 40 mg per gallon.
- For active infections (visible symptoms present), I typically will up the dosage to 60mg/gal. However, I cannot say if this is anymore effective than the "standard" 40mg/gal dose.
- For Uronema marinum and really bad infestations, you can dose up to 80mg/gal. However, I have noticed appetite suppression and lethargy at this concentration.
As you can see, there is quite a bit of wiggle room between the minimum & maximum dosage. Practically speaking, 40mg/gal will treat all external protozoa issues… its just that the higher dosages may get the job done a little faster. Treatment lasts 30 consecutive days, and no carbon, UV, etc. may be used during this time (although it can be used later when you wish to remove the medication from the water.) A little quirk about CP is that light will degrade it; however it appears this mainly applies to the powder itself, so store your CP in a cool, dark place. Once in water, you may use an aquarium light with CP - however fish with velvet
are light sensitive so I would only use ambient lighting (ex. lamp across the room) if treating for that. CP is
NOT reef safe. In addition to killing your corals, it is a very strong algaecide.
Pros - Gentle on
most fish (see
DO NOT USE list below), a “one and done” medication that treats most external protozoa. CP is the closest thing there is to a “wonder drug” in our hobby.
Cons/Side Effects - Expensive, hard to get (requires a prescription), powder is heat & light sensitive - so store in a cool, dark place. Attempts to feed CP laced food are usually not successful due to its bad metallic taste.
** Based upon anecdotal experience (mine and others),
DO NOT USE CP on Anthias, Wrasses or Hippo Tangs. For the time being, chelated copper (exs. Coppersafe, Copper Power) is the best alternative to use on these species.
**
** Finally, a place to buy Chloroquine:
https://www.reef2reef.com/threads/a-place-to-buy-chloroquine.252610/ **
Edit:
@HotRocks beat me to it lol
