The verdict seems to be that some species of fish do well in this type of environment while others don�t.
A friend of mine did some research back in his college days at Rutgers. His research included density experiments involving HSB and different size cages. He concluded that HSB don�t do well in any cages with water that has low hardness. He needed to add calcium chloride to increase the hardness and in addition used a great deal of lime as well. According to him the results where in the end always the same. There was significant mortality and those that were able to survive were sufficiently stressed that feed intake was poor. Even in optimal conditions the tight quarters would lead to diseases like columnaris. He also mentioned that improper handling at the fingerling stage would have a significant impact on them as well. We did not discuss the length of time the fish were in the cages.
