Also if you do a search on water parameters in the rivers where these fish are found here's a couple of examples the xingu river is found to average 84 to 86 degrees the lower xingu river is higher 87 to 91 degrees this is more than likely why Gangster and Boosten are telling you 84/86. Now because I'm a brokopondo lover researching that it tells you basically the same water temps at 5 to 25 meters in depth 84/86) but the 0 to 5m depth the temps average 88 to 91.5 degrees I would have to assume that's where you would find smaller bass in the shallows and this is just from various sources online and from what I remember of the top of my head there is also info for all water parameters too if your interested in digging in further (this is where the hith discussions come in for larger bass). It doesn't mean that these fish wouldn't tolerate lower temps or be detrimental to them, this may be why you are getting so many opinions on what temp to keep your bass in. But the sweet spot is 84/86 degrees.