How long could I keep a Silver Arrowana in a 125 if I get it when it is 5inches. I plan on getting at least a 220 in the next 8 months. Also could I keep it with a blood parrot and a tiger oscar.
Silver aros grow about 1-1.5" per month. So a 5" silver aro will out grow a 72"x18" 125g tank in 7 to 10 months. You will eventually need to get a bigger tank then a 225g. You should be thinking of at least 300g and a footprint of 96" x 30" minimum.