Hello,

I have a 150 gallon tank that is already established. I have a couple of channel cats, 4 silver dollars, 2 parrot fish, 2 gold fish and a pleco . All of the fish have been in this tank for 5+ years. I REALLY want an Oscar because I like them alot and had them years ago. Would it be okay to add one into my current setup or do I need to remove all of my existing fish before I can have an oscar? Thanks for your help! : )

Hi there and Welcome!

You are good to go on adding an Oscar to that tank with the exception on the Goldfish... Goldies are cold water fish, and Oscars are tropical! There for their water temp requirements are different!

But Catfish, SD;s and plecs make good tank mates!

one other thing to keep in mind, although your tank is of a good size, you will need a LOT of filtration!

I'm not too worried about the goldies, they were feeders for the channel cats but decided to stay a while. : ) Now if I get a 1-2" oscar, can he defend from the channel cats and the parrot? Those are the only two that are known bullies, but like I said, they accepted the gold fish.

As far as filtration, would one oscar make that much a difference? Presently I have a big wet/dry filter (I think you guys call them sumps?)that pumps about 600gph with a uv steralizer on the return line. Also I do 20% water changes weekly and have never had a problem with algae or cloudy water. That being said, I dont want to have a problem!! : )

Your filtration sounds like a good set up for the Oscar too.
You should go get a water test kit (liquid type) this way you will know what your water readings are if you have an issue or a question!

How big are your channel cats? I have one that is about 7 inches long, and all he does is hide! LOL

frankiesgrill wrote:


Good Good. I recommend doing 40%-50% weekly waterchange as opposed to 20%.

Keep up the good work.

Channel cats are about 10". The tank is mainly peaceful except the channel cats try to eat whatever can fit in their mouth and the parrot bumps everyone. I figure an oscar can hold his own especially since he will outgrow everyone. I would love to have one or two oscars alone in that tank but I really don't want to remove everyone else. : )

When I had oscars in the past I had two oscars and two albino channel cats that were all raised togethere and didn't have a problem. Now I have mainly smaller fish... I am def going to try it out. I'll get into the water testing. The only thing I ever really test is ph since the filter is good and the water changes are frequent. I'll search on here for the proper levels and see where I'm at. : )

Was afraid to do that much of a water change at a time but I LIKE the idea and will do on the next change!

Most of us do about 50% per week.. I think the water companies really like us! LOL

The only thing I can tell you is give it a shot, make sure you have a back up plan... If for some reason you have to remove someone.

The other think I would like to give you a heads up on, feeding live feeders is NOT a good idea for your Oscar... The carry a TON of illnesses, and goldies are not good for your Oscar. Oscars can not process fats and goldies are full of fat!

Got it, I've been reading up on diets and think I will go with pellets, worms, shrimp etc. Thanks again! : )

Hi, can you get an Oscar that is a bit bigger...say 3 or 4 inches...Little ones can get chomped and a lot of Oscar bravado and aggression comes with age and proven dominance in a tank...just a thought...Shaz

I keep my gold fish in a heated tank, they can tolerate temps of 30 degrees mine are on 26 degree and the types I have (Ranchu especially) it recommends temps of 24degrees. But I think goldfish and O's would be a very messy tank.

small oscar can be safe with that big catfish if the catfish is well feed..
however, if you are out for a day or two and no one to feed them, your
little o will be in danger... plus some parrot fish is a fin nipper...
what type do you have?