“Will a 90g work”
I mean… I haven’t seen to many “true” 24” jags in the hobby in my 30+ years. And any of the guys who’s got them to that size generally have massive 500+ type setups.
However that said, anyone can grow them Out to 16-18” just because they are what they are. Clean water and diet, their genetics will take care of the rest.
I say all that to say this, you honestly think it’s cool to have a 16-18” fish in a 4’ tank with its body length as the depth front to back for them to turn around in?
If so go for it, if not, it’s probably best to pass on the idea.
I’ve kept them several different times over my years in everything from 55g grow outs to 240g spawning pairs.
They grow fast, from 1” to a foot in a year at least.
If I was to keep them ever again, I’d def go with a 6’ x 2’ minimum. But looking back if I could a swing it I’d go even bigger.
Honestly it’s probably just cheaper to do a indoor pool/stock tank lol. I been out of the big tanks for so long I’d probably have a stroke looking at prices of them now.

🤷*♂️🤦*♂️