alittle history for ya, my 125DT that is salt water now once held all at one time the following.
7" red oscar
7" tiger oscar
9" albino tiger oscar
2 foot thats rite 2 foot south american red tail catfish
5" jack dempsey
1.5 foot arrowanna
the arrowanna was 4" big when i got it, and the rest were no bigger than an inch. still do this day i cannot and have tried to recreate this. just dont happen. i dont know what i did for them to get so massive, i mean the catfish alone when he would stretch his jaw, you could easily fit a soft ball in his mouth. these thing were huge. i feed them live gold fish, thawded out shrimp, the catfish would hand feed whole pieces of chicken cutlet. these things were serious. then one day, BANG tank crashed never could replicate it.