Oh No! I have ich! What do I do?


First, lets confirm you have ich. Marine ich looks like you have small white grains of salt sprinkled on the fish. Like the pictures below. Flashing can be sign that your fish is coming down with ich. (Flashing is when a fish will scrape themselves along the rocks or sand, like they are itching themselves.)


Treatment Options:
1. Do nothing! Many fish are capable of fighting the ich off on their own if they have the correct living conditions (right sized tank, correct tank companions, and good water quality) and are being feed high quality food (and they are eating it, very important!) such as a rotation of different frozen foods. It is very important that they are in a STRESS free environment and they are still eating a healthy amount if you choose this treatment path. You also need to remember that the ich will always be in your tank with this method and could come back if the fish are subjected to stress.

For the next two treatment options you absolutely MUST do this in a quarantine tank. They will destroy the biological filter in your display tank, and in the case of copper will make it so that invertebrates can never live in your tank again. You also must treat ALL fish in the tank. If ich is introduced into your tank, you should assume that every fish is now carrying it, whether they are showing symptoms or not. If you only treat one or two fish that have visible signs of ich, it will just get passed back to them as soon as they are put back in the tank with the other fish.

2. Hyposaloinity. This means lowering the salt content of the water to levels where the fish can survive the parasite cannot. This treatment will also kill invertebrates because they are not as tolerant of different salinities as fish. A detailed description of how to do this treatment is in the link below.

3. Copper Treatment. Copper is fatal to the ich parasite, like most bacteria and invertebrates. This treatment should not be attempted without a copper test kit because the levels of copper in the water can be fatal to the fish you are trying to treat, especially if they are already stressed from having ich, and you need to keep the level of copper high enough to ensure totally kill off of the parasite. Below is a link that explains how to treat with copper.

Methods 2 & 3 are the only proven methods of killing the ich parasite. The ich "cures" that are reefs safe only kill off one stage of the ich parasite's life cycle.

Also, invertebrates like corals, shrimp, crabs etc dont carry ich, but the water that you brought them home in might have it, so never put that water in your tank!

If you wish to remove the ich parasite fully from your display tank it must sit fishless for 8 weeks. The ich parasite requires fish to complete one part of its life cycle, so by leaving your tank fishless for 8 weeks you kill the parasite off by not allowing it to complete its lifecycle. Below is a diagram of the ich lifecycle.

Every fish you introduce to your tank after leaving it fishless for the 8 weeks must be quarantined and treated to ensure that it wont carry in the parasite. You can safely assume that every fish you buy will have the parasite, unless it has already been treated (some LFS keep their fish in copper solutions). However they should be quarantined for a minimum of 3 weeks to be 100% sure they arent carrying the parasite. It they do show the parasite, you need to treat, and then AFTER the treatment watch for another 3 weeks. It is a very time consuming process but an ounce of prevention is worth several pounds of cure.

The quarantine tank doesnt have to be a full sized tank, just a moderate size for the fish you are quarantining. So a clown wont require the same sized tank as a full grown large angel. Most fish can be safely kept in 30 gal tank. Many people have success using large rubbermaid tubs. There should be some large PVC pipe pieces in there for the fish to hide in, along with adequate heating and water movement. The quarantine tank should not be plumed to your display tank! You will need to test the water daily for ammonia, nitrate and nitrites and when the levels get high should be changed with clean, newly made water (but at least 24 hours old, new saltwater is very caustic) and this water shouldnt come into contact with your display tank water. Anything that is in the quarantine tank (except the fish being treated) should stay in the quarantine tank so you dont cross contaminate. This includes nets.

Now that you have treated your fish you need to know WHY the fish got ich in the first place. I personally think this is the most important part of treatment. Fish normally fight the parasite off and it lives in a healthy balance with the fish. It is usually only when they are stressed that the ich can fish off the fish's immune system and you can see the clumps of parasites.

Possible reasons:
1. Tank is too small! This a very common problem, and usually results in the death of the fish because the stress never goes away for them to recover from it. You should look for a correctly sized tank ASAP! I recommend giving the fish to someone who has the correct sized tank, and then if you want the fish back you can get it when you have the correct sized tank set up. A good place to check out recommend tank sizes is below.
Saltwater Fish: Marine Aquarium Fish for Saltwater Aquariums

(I also recommend checking out this site for the correct tank size before you purchase any fish. Research before you buy, dont always trust your LFS, remember they are here to make a buck, and avoid this common issue)

2. Tank is overstocked! Take careful stock of the fish you want and can adequately take care of. Then get rid of the extra fish.

3. Water quality isnt good! Do more frequent water changes and watch how much and what you are feeding. This can also result from an overstocked tank.

4. Poor tank mates! This can result from incompatible fish being put together (for example, triggers and butterflies or tangs and morish idols) or some sort of bullying going on. If in the case of incompatible fish, pick which one you like better, and remove the other. In the case of bullying there are a few tricks you can try. A few day blackout, rearranging rocks, or taping a mirror to the tank so the bully fish has some else to pick on.

5. New fish in the tank! This is the easiest case to solve, and will likely go away on its own, just make sure they are eating, no bullying, tank isnt overstocked and water quality remains good.

Good Luck!
Last edited by a moderator:
I would like to add to the very beginning of the article:

Flashing can be sign that your fish is coming down with ich. (Flashing is when a fish will scrape themselves along the rocks or sand, like they are itching themselves.)
The thing on hypo treatment says to do %35 + water changes every other day. If your doing a 40 gallon quarantine than that's a 14 gallon change every day. Salt is sold at foster and smith's for $43.99 per box. Each box can make 200 gallons of saltwater (with sp 1.022). If the sp in the quarantine is at 1.009 then that means that the box is enough for about 500 gallons. That will last about 70 days/ 35 water changes. So quarantining one fish for about 8 weeks uses a box of salt.

That's actually not that bad, I though it would be a lot worse...
Oops, I forgot to include the fact that the tank will be at regular saltinity for 4 weeks. It probably ends up being more like 3 or 4 boxs...
I think you are better off testing daily and doing water changes when you see any levels rise. So make sure you have water made up on hand.
OMG I bought a flame angel from a new LFS on their first day opening. Turns out that two days later he appeared to have some "white faded area" in the back the next day he stopped eating and was dead by morning! Problem is that I have a 300 gallon tank which fish wise has been going perfect. Now I have a fox face with about 6 spots on him, a Vlamengi tank with a botch of white faded area and a old cardinal (5 years old) with frayed fins and a blood like spot at the tail and side fins. Everyone is eating great except the cardinal and yesterday I started treatment with the no ich medicine from Rally. I went back to the new LFS and every fish and tank had ich! Over 50 tamks so I am positive the Flame was the culprit! Any other suggestions please? Temp at 79 so should I raise it? Or do I just continue treatment and hope fish will beat it out (except cardinal, might be too old and fragike at this point). I don't think I have misdiagnosed but maybe tang has oodinium? I appreciate your ideas you guys are awesome!!!! Don't have quartantine tank.
In a 300 gallon system your best to just let the fish beat it out,,,but its always there now.. white blotches is a sure sign of stress too,,,what all is going on in your tank?Personally i would stop the ich medication and try to keep things as normal as possible in your tank.,it won't work anyway.....good luck
Ok my PH is 8.4, nitirte and ammonia is 0,Nitrate is 50, did 50% water change about 4 weeks ago. Temp is 79, phosphate is .5 Fish are swimming and eating normal. Clown, longnose hawk, bi color angel and two royal gramma's have zero signs of ich. Majestic angel has no sign of ick either. Third Royal gramma has one speck, magnificant foxface has about about 10 specks on one side and 8 on the other side that I can see. Vlamengii tang (about 12 inches long) has about 2 specks on one side and one on the other. Vlamengii also seems to have a bacteria infection also with whitish area about 3/4 to inch on one side and along top fin. Two serpeant starfish, coral banded shrimp and cuc snails all doing fine. Only loss today was a small cardinal fish that was about 5 years old.
As long as they're eating normally they should fight it off themselves. I would up the frequency of water changes to bring down your nitrates and phosphates.
"When salinity is lowered the bacteria sometimes enter into a state of suspension and hold off in their metabolism of ammonia and nitrites."

If bacteria can live in brackish water then why can't they survive the hypo salinity treatment?
they are a different species of bacteria, that have evolved to live in those conditions. Same job, different dude

So if I have brackish live rock and put it in once the S.G. is down it will help eliminate the ammonia and nitrites? I know that's a silly idea but doing a large water change every 1 to 2 days is a lot of work, and expensive. And my RO/DI unit would hardly be able to produce enough water even if it was running 24/7. I guess if I ever run a quarantine tank I'll be using tap water...