Learn something new every day.
More like there's a sucker born every day.
Yes, "bloat" is typically caused by internal flagellates, in tropical fish usually Spironucleus vortens, something that I have only mentioned several dozen times on this forum over the years. Will that come across as more credible if I add a PhD after my name? If so, just call me Dr. Neil.
In a healthy fish S. vortens is commonly found in the flagellated stage in the lumen of the upper intestine where it is controlled by the immune system of the fish. In a stressed fish, the immune system becomes compromised, and these flagellates multiply unchecked causing serious localised damage. Once the damage is severe enough the intestinal lining is penetrated and the flagellates enter the blood stream causing systemic and organ infections, failure, and ultimately death of the fish.
If/when diet is the cause of bloat (which IMO is seldom the case) the trigger is caused by poor quality ingredients that the fish has difficulty digesting. (usually cheap grain fillers) If a fish can't digest the food, then it can lead to impactions in the gut. The fish stops eating (as it can't pass what's already in it) the impacted area goes septic from multiplying bacteria, and the result can be (and quite often is) deadly.
The science is clear on this, there is no debate.
Salt only becomes an issue if the fish is already suffering from bloat symptoms, due to the fact that by that point the fishes organs are beginning to shut down, and due to the osmoregulatory stress caused from that scenario the last thing you want to do is add additional stress by increasing the sodium levels of your tank water.
While I do not personally typically add salt as part of a regular regimen with any of my freshwater fish, doing so will not cause bloat in cichlids. Anyone that suggests otherwise is spending too much time drinking from the fountain of stupid. And as Jeff suggested, salt is just a wee bit cheaper than the drugs the boys at National Fish Pharmaceuticals are selling.
I think that, as you and most probably do, as generation after generation are being born into tanks, they are able to adapt better to stress/ man made diet, the chemicals in said diet, the water we have them in & the chemicals we use to treat their water. Maybe in a few yrs if not sooner, we will all be able to keep beani the way we do most Amph species. With ease.
I think that's wishful thinking. There are numerous cichlid species that are prone to bloat, many of them found in the Rift Lakes & even those removed by hundreds/thousands of generations from the wild, bloat is still a major issue in keeping them thriving in a glass box. It always comes back to stress as being the trigger that causes bloat in all of these various species.
For decades Tropheus keepers felt that due to the intestinal length & long digestive process in that species, it should only be fed low protein "green" food, and that any amount of animal based protein could cause bloat. Yet science has proven that in captive bred species of Tropheus the intestinal length can be half of what's found in wild specimens.
Intestinal prolongation, although indicative of specialization on diets with low nutritional value, such as those of epilithic algae and detritus, has been shown to be highly plastic (Sturmbauer et al.1992). In Tropheus moorii the intestinal length of domestic fish measured only 50% of the length found in wild individuals (Sturmbauer et al. 1992).
A more recent study that was published in 2009 demonstrates just how great intestinal plasticity can be in response to the diet quality of a fish in the wild.
http://limnology.wisc.edu/personnel..._Functional-Ecology-LT-cichlid-gut-length.pdf
While I agree that captive bred species will generally always adapt better to aquarium conditions than wild fish, the above clearly demonstrates just how adaptive cichlds can be when it comes to their diet. As long as one feeds a quality food, diet will be a non issue, and will not cause any type of major gastrointestinal stress. Apparently with Beanis, even live mice can be eaten without issue. lol
The bottom line is the vast majority of stress that's created in an aquarium, is done by the hobbyist themselves while attempting to push the envelope. Some fish can handle the stress of constant aggression from fellow tank mates in comm settings, some fold under the pressure. Sometimes just adding
one more fish can cause the whole house of cards to come tumbling down. Some hobbyists come to understand the limitations of their tanks & fish early on, some never figure it out.