According to swai farmers they reach market size(2-3 lbs) in under a year, some as quickly as six months, and have a far better feed conversion ratio than channel cats. If the fish are staying small it's almost certainly some failure in husbandry. I'm not passing judgement as it seems many who provide what we would consider at least decent conditions have the same issue.
Right and all agreeable, except maybe the feed conversion ratio and the undeniable fact that a large % of IDSs sold grow slow and small in proper care.
Other things than improper husbandry may explain this "seeming" contradiction. Albeit hard to support by anything.
I offered these worthless thoughts in a couple of other threads:
"... There is this notion that some farmed ones, such as Hemibagrus nemurus (most often albino), IDS, etc., are poor growers, which I don't understand as this would ruin the food fish farming business... but, indeed, we have been seeing fishes of abnormally slow growth and attaining much smaller adult sizes, it would seem of both hemibagrus and the IDS. Some suppose this is due to insufficient attention of the farmers to the maintenance of a healthy gene pool - but this can't be agreed because, as mentioned, it would ruin farmers' business...
The usual thought/conviction is that we in the trade get a tiny % of the fish raised for food.
This conundrum could be reconciled by a supposition that the ornamental fish trade is now getting supplied from a different source than food fish farms and the ornamental fish trade may even benefit from smaller fishes as more hobbyists can house them. They would also benefit as these fish would reproduce poorly too (and are more sickly). All this increases the "ornamental farmers" consumer demand and farmers' security. ATM, this is but my wild thoughts, unsupported by anything."
This is probably just silly thinking. Grasping at the straws.