Fellow Reefers.

Now I have already written a guide on cupramine and how to use it to rid ich and for a lot of reasons if someone does not want to try copper then Hypo is another solution or Tank Transfer. These 3 methods are proven over time.

A new study/method is being practiced with success by using a chemical called Chloroquine Phosphate. In this guide I will try to explain as much as I can in detail how to perform this treatment with much success.

Please respect this guide as my personal experience and treatment method and NOT by any means a 100% guarantee. This has worked for me few times so please use caution and improvise if something is not mentioned and use this guide as knowledge and not as set in stone.

First off have a QT setup.

If you don't have a QT setup please look up threads explaining how a QT is setup. There are different ways to setup a QT. More than one way works the same for Hypo.

One you have a QT setup:

I strongly recommend use of a very reliable refractometer and ATO (auto top off system)

A tang with marine ich (and possibly other things).

Photo is from the Reef2Reef archives. ©2019, All Rights Reserved.

Day 1: Buy your fish from a well established/reputable source.

After bringing the new fish home, do not open the bags. Acclimate them by letting the bags float for 15-20 min. Check the salinity of the incoming water and adjust the QT to that setting. Once bags are opened acclimate new arrivals using drip method. Once acclimated transfer to QT. Leave lights off for the first day and let the fish adjust to new environment.

Day 2: Turn lights on and observe for any signs of disease.

On second day, observe for disease. If everything looks normal proceed to prevention mode. Use Prazipro according to manufacturer’s recommendation for 1 week. After first week do 25% water change then dose Prazipro again according to manufacturer’s recommendation. Wait another week do a 50% water change.

Day 15-16: Water change.

After 15 days of observation and prevention medication, CP is ready to be administered. We have already performed 50% water change previous day so I recommend another 50% before starting CP.

Day 17: Chloroquine Phosphate CP.

CP is a white powder chemical that is used in a class of drugs called antimalarials and amebicides. It is used to prevent and treat malaria. It is also used to treat amebiasis.

The most common dosage for CP is 40mg/Gal.

Mix the dose according to your tank size and let it do its job for 30 days. After 30 days do 50% water change. Next day or two follow up with another 50% water change and use of carbon to rid all CP out of the system. Now observe for another 2 weeks and if there are no signs of ich then you are ready to move fish to main tank.

Note: In some rare situations and in some fish you may notice around 15-20 days, Fish might act lethargic and may lose appetite. If that happens, Pull the fish from CP tank to a sterile tank for observation and recover for at least 2 weeks. At the end of 2 weeks you may have to run CP again if symptoms exist.

Ich Emergency.

This guide is prevention and method explained above is with assumption that fish are new to your setup and may or may not be infected with ich parasite.

If you have fish that is known and confirmed of infection then don’t follow the steps above. Jump directly into placing the fish in QT doing proper transfer (acclimation etc) and dose tank with CP. Once treatment is over after 15-20 days do 50% water changes over few days and then use Prazipro for 2 weeks and observe for another 2 weeks.

I hope I have provided a good enough procedure for people to follow and wishing everyone Good Luck and Safe reefing.

Note: if there is an error or I left out something or you would like to add on to this please feel free to post.

Thanking You

Reef Doctor


This is a royalty-free image from Pixabay.


Note from the Editor: Please note that chloroquine phosphate typically requires a prescription from a veterinarian or a medical doctor.


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Author Profile: @Dr. Reef

Dr. Reef is a valuable member of the forum and #reefsquad who often helps with fish disease issues.
Dr. Reef is a real doctor who has been keeping reefs for 30 years now and practicing medicine on fish for last 15-18 yrs.

He has a 300-gallon in-wall display tank and several other tanks for experimenting with treating sick fish.