Batboi3000;5094934; said:I would think a 6 foot tank should be big enough for a breeding pair of jags. At least for a good while. So long as the tank is at least 18" deep.
On your 8 footer, what are the rest the dimensions/gallons? I would agree with some of the current responses by saying the festae may be too much aggression for the rest the stocklist. It still may be worth trying. You could possibly even do a couple more fish than that. I guess if it were me with an 8 foot tank with that stocklist I would probably do something like 2 oscars, 2 jack dempseys, 1 jaguar, 1 texas, maybe even a green terror, your pleco and start there. There's a lot of options. Good luck!
Maybe read the first sentence in the first post