Hi I currently have two oscars and two plco catfish in my 300 gallon tank. I would
like to house four oscars and the two plcos. As of now the water quailty is great, but
I have two small oscars in another tank that will have to be moved. I do 20% water changes twice a week, and seem to get along fine. I have read where
oscars seem to get along better with more. My concern will the tank be overcrouded.
thanks for your thoughts.

one think you have to keep in mind is that theay will grow you should have enough room but then again u dont know how big theay are going to get if you have common plecos u are looking at approx 2 ft each pleco when full frown

What type of filtering have you got? If you have got a lot of filtration then you probably would be okay. However, I'm not keen on plecos, especially the ones that get very big, they will create a lot of waste and this could actually tip the balance when it comes to water quality.

I think 6 Oscars would be better if filtration is adequate. A general rule is 1 oscar or atleast 6. This method is believed to decrease the Oscars territorial and competitive nature. Again this is just a general rule. 4 could be just fine. To answer your question, yes your Aquarium should be capable of handling your fish just find, provided proper maintenance and filtration is performed. I would love to see pictures!

I have a canister filter that is rated for 260 gallons. and I added bio wheels with this system, also have a Imperial 400 hang on filter with bio wheels which is rated at 80 gallons. The two plecos are the ones that will reach 2 foot, they are 1 foot now and one oscar is 12 inches and the other is 8 inches. The one that is 8 inches is more territorial than the larger one. I also do 20% water changes twice a week. I have been thinking of moving the plecos or giving them to someone who wants them. I will see what I can do about pictures.

with adequate filtration and some barrier inside the tank, yes you can.