so im new to owning oscars and was in the market for a red oscar..went to my local fish store and they were all out but they had a blueberry oscar..i thought to myself wow he looks cool ill just get him...well after getting home i did and little research and found out its not a real strain of oscar and is in fact dyed..now in no why am i for this treatment to fish but am just curious if anyone has any tips on keeping the oscar as healthy as possible..i read that it weakens their immune system and they dont live that long but i would like to make its life as good as possible and hopefully extend it as long as possible...Its only about 2.5 inches so hopefully it wasn't in the dyed water for a long period of time...thanks in advance

If you want to keep them as healthy as possible then just follow all the tips and proper fish care informed on this site. I guess if the dye had effect on the oscar then it should affect its lifespan. So it all goes down to if it's his time then it is. This site will be very helpful to you as it was and still is for me.
As for the basics:
-don't buy the oscar yet. Have your tank cycled first.
-50gal-75gal tank for ONE oscar.
-water test kit is a must.

here's the link on how to cycle a tank..
oscarfishlover.com/how-to-cycle-a-tank

and have I misread your post? have you bought the oscar already?

yeah i already bought the oscar..so i just wanna try to keep it as healthy as possible...thanks

Have you cycled your tank before you put him in? How big is your tank?

i have a 35 gallon tank that has been setup for about 7 years...for the past 5 years ive only had a pleco and a couple small catfish that ive had for about 10 years...the catfish recently died so i wanted an oscar...i know 35 gallon is a bit small but he is real small right now and i plan on upgrading if he lives a long life and gets big...i did add the bacteria to the tank when it was first setup but like i said it was 7 years ago...i dont have any live plants. should i invest in some?

Live plants isn't advisable when you're keeping oscars because they will just gonna rip them out. Oscars have an habit of redecorating they're tank on their own so live plants would be a waste. Since your tank is already running for that long then you just need to maintain perfect water condition for a healthy life of your oscar. Do you have a water test kit? If not, you need one. It's easy to determine the problems that needs attention when you have one.

no i dont have a water testing kit but will go buy one tomorrow...i just hope the dye didnt affect him to much. hes very active and has a great appetitte...guess all i can do is wait and see

If he's active and eating fine then he should be okay. We also love to see some pics!
Oh one more thing, you're planning on upgrading on a bigger tank right? You might wanna make it sooner because juvenile oscars grow very quick. He won't stay 2.5" for so long.
I had mine 2" when I bought him 6 months ago and he's 7" give or take now.

Obodobo got you covered.
And i couldn't aggree more on the need for an upgrade of your tank.
If you take good care of your ocsar he will grow FAST!
Reaching the 7 inch in 6 months is not uncommon, and mine passed the 10 inch in just a year.

Are the catfish still in there?
If they are, mind you that your Oscar may like them very much.

nice 2 hear u dont agree with dying but if u didnt know, as u say, best thing u can do is give it the best life u can, my advice is upgrade yr tank and keep a regular check on water params as i assume a dyed oscar will have a lower imune systema nd defenses than regular o's

I agree with all that has been said, let my just add, that it is VERY possible that your Oscar will out grow this dye. So don't be upset if he turns out to be a red...