Hi all,right i have a 4foot tank with over siezed external filter which has been running for 3 years now without problems. The current fish are 1 common plec(10-12inch) 4 siver dollars(5-7inch) 1 black shark(8-10inch) 1 flying fox(5-6inch) 2 kissing gourami(2-3inch) 3 danio devarios(2-3inch) 1 kribb(2inch).I would love to get an oscar in there but would love some advice first! Thanks in advance chris.

welcome to oscarfishlover

Unfortunately, I think you're probably a little bit overstocked with the fish you have got to already , so adding an Oscar is very unadvisable.

According to thinkfish.co.uk im well understocked,but im not doubting you. Any ideas then? Say i get rid of the fox,kribb,2kissers & 3 danios wold that help do you think?

As OFL has pointed out you are at your limit with your fish already. to add a oscar to a 4ft tank( I would think thats around 50 to 60 imperial gallons) would make large water changing a daily event. a 60gallon tank is a good size for one oscar with no tank mates. I would say get another tank for an oscar. a 4ftx2ftx18" would fit one oscar and if you want more than one look at 125 or 150 gallon tanks