Hi everyone,

My tank has several cichlids, including two 11" oscars.

however, both of them has severe deformities!






Is this the head in the hole disease? I've been away from home for a long time so my parents have been feeding koi fish food to them all this time. I went out to get fish food designed for cichlids and now the vitamin c nutrition has increased from 75mg/kg to 14000mg/kg.

I did a water test and there are no traces of ammonia and nitrate. however, pH is 6.0

what actions can I take to save my oscars?

also, can you please identify the specific species of the other cichlids you see in the photos? I don't know what they are..

Welcome to oscarfishlover

Looking at the top picture, one of your Tiger Oscars looks like it has quite a bad case of hole in the head disease. You said your ammonia and nitrates was zero and your pH was 6.0. Ph is okay. Ammonia is good, however are you getting confused with nitrites and nitrates? Your nitrates won't be zero, I can absolutely guarantee that. Your ammonia and nitrite should be zero, your nitrates will depend on tank size, how many fish you have, and also tank maintenance. There must be some reason why that fish has got hole in the head, it most certainly has something to do with poor water conditions. I couldn't really tell how big your tank was, but you've got quite a lot of fish. You should have well over 100 gallons for all of those.

The first thing you need to do is doublechecked your water readings, ammonia, nitrite, and nitrates. It's absolutely vital we know the exact readings. Also, can you please get some better photos of the Oscar that has hole in the head disease. I want to determine how severe it is, it will give me an idea of whether you need medication, or whether extra tank maintenance will be all that is needed. It does look very bad, I suspect you are going to have to get some medication to help kickstart the Oscar into recovery. However, we can't do anything like that until we know your water is in tiptop condition. Unfortunately, depending on your tank size, it may mean finding a new home for some of the fish.

Regarding what the other cichlids are, not sure about the small one in the second picture, the large Cichlid in the first photo looks a bit like a Texas Cichlid, I could be wrong, I'm not really an expert on other types of cichlids

Anyway, time to get my head down, very late here in the UK so I won't be on-again till the morning

Hi OFL,

Thanks for your reply.

I redid the water test and the results are as follows:
pH: 6.0
nitrite (not nitrate!): 0
ammonia: 0 (there seems to be an *extremely* faint tint of yellow that is barely noticeable, or maybe caused by the indoor lighting).

The tank is 200 U.S. gallons. I will upload new photos as soon as I can.

I also wanted to know how many fishes a tank of this size can support. So far there are two 11" oscars, 1x 7" texas cichlids, and 3x 5" unidentified cichlids. I've been wanting to introduce some new fishes (silver dollars in mind) but I don't know whether the oscars will eat them since they come in sizes of 1.5" to 2" at petsmart.

Thank you!!

can you get a reading for your nitrates. if your filtration is good your ammonia and nitrites will be a zero from the bacteria in the filter however your nitrates cannot be removed this way. water changes are the only to reduce them.

as for your other cichlids i also think the big one is a texas as for the smaller they kinda look like africans to me but im no expert.

with a 200 gallon tank you should be able to get some silver dollars without too many problems.


btw welcome to the site

before you start adding any more fish, let's get your Oscar sorted out first. We certainly don't want it getting any worse than it is at the moment.

What puzzles me is fish don't develop this severity of hole in the head disease for nothing, something must have caused this to happen. This is why we must know what the nitrates are.

Have you got any other tanks that can be used as a quarantine tank? Preferably a lot smaller than 200 gallons, 40gs would be perfect. Hole in the head medication isn't exactly cheap when you are treating that amount of water, you're much better off putting the Oscar in a much smaller tank. However, before you start any medication, let's get your water in really good condition, nitrates no higher than 20 ppm at any time, preferably lower. I reckon if you can do that for two or three weeks, you should start seeing an improvement and you may be able to clear this up without the need for medication.

Hi. I did the nitrate test and the results are in. It is or close to 0ppm.




BTW, here is my tank (suggestions/improvements highly valued!)




Here is the oscar with the severe holes:






The second oscar do have holes but not as severe. How often should I feed them? The food carton says 2-3 times daily but the website here (and others) says once a day for oscars of this size... I am also concerned about the "browning" of the oscars. the belly area seems to be turning brown--what does this mean?

I have a 25 gallon tank that is currently being occupied by 3 medium goldfishes, 1 koi, and 2 turtles..

have a look at this guy my mrs saw him and fell in love he he

ill try again

and again

Hey OFL, I want to hear what do you think of the situation now that I uploaded those close-up photos per your request.

I've been feeding cichlid-specific food to them instead of koi food for a week and it seems that the more shallow holes are beginning to heal. Or maybe I am just optimistic.

I stopped by Petsmart today and the two women who work there says that I can't introduce 2" silver dollars to the tank since they oscars are territorial and has been established (they are 2 years old). Does this mean I can't add any more cool fishes?

you should keep silver dollard in 4-5s as they are much happier but i would not bother untill you sort your poor oscars out..

you say you go to petsmart were in the uk are you?

I'm actually located in the U.S. (California)