I have the chance to rescue two tiger oscars both 7-8".

They were living in bad conditions, done ammonia test and fluid went black. Never seen anything like it.

However what is the chance of adding them in with my oscar harry 8".

Told you should have one, others say two. 3 maybe ok.

From experience what is likely to happen if they all go together. Is it possible they will all just get along or is that just dreaming.

In two weeks they would all be going in my 600L tank.

Whereas I wouldn't normally recommend putting three Oscars in a tank your size, I feel that they would probably have a better chance of survival if they were in your tank. As long as you've got really good filtration and you keep a close eye on the water conditions, I think they'll be okay. However, I wouldn't look upon it as a long-term commitment. Remember that Oscars can reach well over 12 inches, three of them is an awful lot of fish for a tank your size, plus any other 50 might have. I wouldn't keep more than two Oscars in my 125 gallon tank, put it that way.

Now, before you move these Oscars into your tank, you have to bear in mind that you might be introducing disease. Any fish that is forced to live in poor water conditions is very susceptible to disease and illness.

It makes me bloody angry when people keep these fish in such poor water conditions, I'm surprised they are still alive, sounds like the ammonia was through the roof

Tank was only 48x12x12

Someone I new was talking to him and he asked for advice and for me to take a look.

Might see if my local shop has a free large tank and can take them. Moving them in with me was just one option.

You dont want to know what the other readings were like. he was also using air feed undergravel for filtration.

That tank is approximately 30 gallons, it's no wonder he was having problems, probably wasn't doing any water changes.

I get e-mails from people asking me advice and nine times out of 10, they are keeping the Oscars in totally unsuitable environments. But I look at it, there's no point in having a go at these people, that's not going to help anyone. I just wish the shops they bought the fish from would make it quite clear how you should look after these fish and what size aquariums they need

Here is one e-mail I got today.

My tank is 12 gallons, Oscar is 5.5 inches. Nitrate and nitrite are within safe range, Partial water change was a week and half ago, new filter, anmonia is 2.5. Water temp is in nornal range, pH was too low and added API pH-UP last Thursday. Oscar is alert and feeding fine. He has a white film along the dorsal fin from his head to tail,bi-laterally. It looks like a white chalk line. Can see a lighter layer over the top of his head and upper back areas. He does engage in some aggressive flashing at times- ususally to get attention (we believe- i.e food.) His fins and colors are fine.

Diet consists of Hikari - Cichild gold Pellets and occasional dryed Krill, last live fish feeding was about a month ago.

Do I need to treat this, is he sick?

Tank was only 48x12x12

Someone I new was talking to him and he asked for advice and for me to take a look.

Might see if my local shop has a free large tank and can take them. Moving them in with me was just one option.

You dont want to know what the other readings were like. he was also using air feed undergravel for filtration.

Tank was only 48x12x12

Someone I new was talking to him and he asked for advice and for me to take a look.

Might see if my local shop has a free large tank and can take them. Moving them in with me was just one option.

You dont want to know what the other readings were like. he was also using air feed undergravel for filtration.

I'm sure they will be better off with you than where they were.
The way it sounds they might be better off dead than where they are now. Good luck to you, i hope you can find or give them a better home.