I've had my tiger oscar for about four years now. I got my oscar as a baby and we've been heathly until now. My Oscar started flashing on the gravel alot and just laid around on the bottom of the tank. I know they lay around alot, but I know this was not normal for my oscar. He would lay completely on one side or the other. My oscar would do this for hours then just stand on tail for hours. The oscar's colors started to fade to pal or greyish. I treated the tank with melafix and my oscar seemed to be getting better. I did a 50% water change and within a couple of days the oscar's colors started fading more. Now my oscar stays close to the top of the tank, not gasping, just hanging out. My oscar will eat a little, but not much. I'm concerened and don't know what to do or what my oscar might have. My tank is 75 gallons and the tank mate is a yellow belly catfish and a couple of alge eaters. This have been the tank mates for years now. I have not added any decorations or fish to the tank. I'm using the same food I always have. Worth noting is the catfish seems brusied. Also since my water change the oscar has cleared gravel from the bottom of the tank in about a 8inch section. I do not see any visible signs of parasites or anything else. My water is cloudy. I've never had this problem before. This is a fully set up tank for years now. Everything has always been fine.
I'm not sure what to do if anyone can tell me please. I do not want to lose my oscar.
Please not this is not patches of pale or gray. It really is like the color is fading away.

Welcome to our community

firstly you need to do water tests if you think there is a problem. I always compare it to go into the doctors. In many cases they take blood because that will tell them a lot about your health. Testing your water will do exactly the same, if there are toxins present then this could be the cause of all your problems. Adding medication without knowing what the quality of is is pointless.

You say your water is cloudy, this could be down to the amount of fish you've got. How big are the other fish? When you do a water change, do you use a conditioner to remove chlorine? Also, have you cleaned your filters at all?

If you can get back to us with some answers to these questions, it will help us to help you.

i go with OFL.
just give us details as OFL had requested!

I Changed the my filters when I done a water change. When I do a water change I do us a conditioner. My Oscar is about 12 inches long and my catfish about the same. The two alge earters are small about 4 inches maybe. I haven't done water tests I plan on going out today and getting the stuff to do so.

I checked my water conditions and everything is normal. Water temp is fine too.

Can you tell us exactly what they are, normal doesn't tell me anything, I need to know the readings.

give the actual water redings ph and amonia

Your problem is I'm sad to say your catfish. How big is your tank? If you do not remove the catfish from this tank immmediatly- you will loose your 12"baby. He's worth saving. The other guy just but him in a bucket and when its warm let him go.

happygrl wrote:


If you are suggesting releasing fish into the wild then I would advise you not to do this. Most countries have strict rules about releasing fish into the wild.

In Australia the European carp was introduced some years ago, whether it was by accident, or intentionally I know not. Anyway, it causes great problems now because it eats a lot of the vegetation which many of the native Australian fish rely on. In many of the rivers it is an offence to put one back if you catch it, I think it's something like a $100 fine if you do get caught putting one back alive.

Whether you like it or not, some fish are just not meant to be in some water ways.

I retested my water and come up with something different than the first time.
The nitrate is 80
The nitrite is 1.0
total hardness is 300
Total alkalinity is 80
pH is 7.2
I used a 5 in one test strip

could there be a problem with me having the catfish?

Okay, your nitrate is very very high indeed. Your nitrate is also quite high. The fact that you've got such a high nitrate reading does indicate that your biological filter is working. When was the last time you did a water change?

Is there any chance you can get some liquid tests, a lot of people don't trust these strip ones, some people have found they give false readings.

It has been a week since I done a water change and did a 50% water change.
I live an hour and a half from any pet store that might do a water test. So I've got to go with the strip test.
What do I do now?