I have a pretty dam big 4ft tank with one oscar and wondering how many mone could go in

What are the other measurements of your tank?(depth, height)
I could calculate the volume for you, and that would tell us more!

It is 150cm long 60cm wide and 80cm high

That would be about 190 UK Gallons.
We advice at least 55Gl for a single specimen, so that leaves you with enough room for another tankmate or some tankmates.
For getting an Oscar may be hard, cuz they'll have to get along.
2 males will most of the time develop aggression issues in time.
Getting a couple may be difficult.
But you got plenty of room for some tankmates.
I got a 180Gl and got 6 silver dollars, a Viela Synspillum, some plecos and a Florida Gar in with my O.
It all comes down to what fish do you like?

188 gallons, at 55 gallons per oscar, thats 3 oscars and a few tank mates. 3 is a bad number. if they pair up the other one will likely get beaten up. id go for 2 and some other fish.


edit - dang noddy snuck that one in on me!

albinotiger wrote:

that would be 187 US gal tank

in most cases, basis of number of fishes depends on what reference are you
trying to figure out. present or future. big tank can accommodate so many
small fishes or young fishes. but how about when they grow up

the basic info when i took up seminar on fish tank business, it is 21 liter
or water for every inch of fish size. thus, a 10 inches oscar requires:
21 x 10= 210 lit /3.85 lit per gal= 54.54 gal @ 55 gal size is recommended.

so your 187 gal tank could house around 17 oscar at 2" body each. but there
will be no room for them to grow,otherwise you will have water issue as they grow.

if you consider full grown oscar, a pair of 10 inches around 110 gal, then you can
have school of loaches about 6 inches big.

the size of the tank, the number of fishes, should always have a matching capacity
of filtration...otherwise, you will have water issue too.

yea like win said i would just go for 2 and buy some other fish to add to it.

You could get quite a few fish in there but i wouldnt go for more than 2 oscars. If get 2 that decide to breed then the others will be in trouble. You can go for tankmates off course. I would say you could have the equivalent of 5 foot long fish. If you get smaller fish like a blue acara (6inches) you can have 3 of them to mean a foot long fish. But remember the more fish you have the more maintenance needed.

What are the calculation of a 30cm high 30cm long 30cm wide tank in uk gallons

albinotiger wrote:

It's 5,94 Gl.
Try the search engine right from the OFL banner.
Search for calculator.
Works well and has lots of "translations" as well.
I'm finally getting used to Inches and Gallons!