Most fish can adapt to a PH as long as it's stable. For what it's worth, Amazonian fish (which includes pbass) come from acidic waters. Some backwaters have a PH of 4.0 to 5.5 at certain times of the year. This is well documented. Several strains of wild discus and cardnial tetras for example are known to spawn in such water. However, a PH in the sixes is more common. Do the research if you don't believe it. To say an Amazonian fish has better color with a PH in the 7s, is a figment of someone's imagination.