+ 3/4 ^^
Flow, current, circulation - all have relationship to GPH but, arguably, are also slightly different concepts. The tank shape, size, planting density, fish species, co2 are other smaller, but important factors.
In short, I do not know 'the right' general answer. It's all part of the fun.
Courtesy * Integrity * Perseverance * Indominable Spirit * and Self Control
Tenets of TKD