my oscar fish is about 2 1/2 inches. its in a 10 gallon tank. the tank has been set up for about 2 weeks with 3 small guppies in it to get the nitrogen cycle going. i have been testing the water and all results are good. however, my oscar fish that i got two days ago is at the bottom of the tank gasping. he rarely swims, and when he does he just moves across the bottom to a new spot. but even that is rare. i changed 50% of the water yesterday and tested the water again. every test looked good. the temperature of the tank is about 75 degrees. i dont know what is wrong with him. i want him to be happy in his new home! help please.

Can you give us the exact water the test results.

Ammonia, nitrite, nitrate and pH

I have to tell you that your tank is grossly too small for an Oscar. Okay your Oscar is small at the moment, your tank will be too small within three months, maybe even less.

You really should have cycle the tank before getting an Oscar. Because dangerous toxins build up in the water when the tank is cycling, fish are put under great stress. Cycling the tank with Oscars should be avoided because they are susceptible to diseases such as hole in the head disease. This can be brought on by poor water conditions.

There are various other factors that can make your fish breathe heavily. Lack of oxygen in the water is one such factor. Make sure that where the water comes back into your tank, it is disturbing the top of the water.

Have you mean using a water conditioner when changing the water?

Anyway, please get back to us with those water readings and try and answer all other questions to the best of your knowledge. One last thing, please do feed your fish too much at the moment, feed it sparingly, you don't want too much waste going into the water. That will just increase the amount of ammonia.

hmm? did you choose that oscar or did the fish store just scoop the first on he saw in the net? if you did choose it was he swiming around then?
i know oscars can be sulky but at a young age they tend to be very active. are your test kits still in date?
could be gill flukes, by the way a 10 gallon is far to small for an oscar unless you plan to re-home him soon

i know the tank is too small, an upgrade will be in the near future.
ammonia-0
pH-7.2
nitrite-0
nitrate-0

i feed a pinch of flake to the three guppies once a day. i fed the oscar yesterday but he didnt eat so i took the uneaten food out of the tank.
when i do water changes i use Aquasafe water conditioner.
i chose the fish at a pet store. he was swimming all around and looked happy.

We weren't having a go about the tank size, we always point this out to newcomers in case they are not aware.

So if you haven't got any toxins present, we can pretty much rule out poisoning. Have a look at the fishes gills, do they look normal? Accelerated breathing can be caused by many factors such as internal bacteria problems, parasitic and at stations and problems with the gills. It can also be as simple as a fish being stressed. Give the fish one more day and see if the breathing slows down and returns to normal. If this behaviour carries on for more than another 24 hours, we may have to look at other reasons that is causing it.

Have a look at where the water comes back into the tank, is it disturbing the top of the water?

Are you sure your testing equipment is working properly or that you did the test right, did you follow all the instructions. To get a zero reading for ammonia, nitrite and nitrate is almost impossible. In a cycled tank ammonia and nitrite will be zero and you will get a reading for nitrate which should be below 40 but ideally below 20

Did you cycle the tank before adding the oscar. Doing a daily water change while he is ill wont do any harm

i thought it could be a low oxygen level. but i am making sure that the temperature is around 75 and where the filer comes into the water there is disturbance. also there is an undergravel filter. there are bubbles coming up through the water on both sides of the tank. i dont know if this is worth mentioning but my other fish are fine. would it be possible for my oscar to have hole in the head? there is a tiny dent close to his left eye...i have never had an oscar before, but i really cannot figure out what else it might be. before i got the fish i was reading material about them for a while and today i have been reading this site all day....i just dont know..

hi there as far as i know Juvies wont get HITH as HITH takes a while to develop due to poor water condition ect.
as delboy said u should get sum kind of a nitrate reading prefably as close to zero as possible although its almost imposible to keep it zero under 20 will be great though.

i suggest u take a sample of yr water to yr local fish store and get them 2 test it 4 u so u can compare their results with yr's just to be absolutly sure that yr test kits are fine.

post a photo of yr oscar so we can have a look at the damaged spot on his head.

keep in mind when u see the juvie in the store he is very alive as he is in a big group of oscars and feel safe with all his mates.

once u get him home he will sulk 4 a while and come around eventually.

hope this helps