LTAs require medium flow . I have my LTA in my 55 with two power heads pointing so they provide indirect flow throughout the tank . It seems to be happy with it and hasn`t moved in years .
My LTA has been quite happy in what I consider low flow.....Barely enough to move its tenticals sometimes....mine as well has stayed put for years....so Im not saying they want do well in medium flow, just that IMO, " require " might not be the proper word to use....
