betta1...
Welcome to Aquarium Advice!!
Personally I think you might be stretching it a little with 8 White Clouds (Tanichthys albonubes) in a 5-gallon hex. The hex tanks are taller (with less surface area) than a regular 5-gallon tank which means less area for oxygen absorption. You can probably safely house 4 of those little gems in there along with some sort of small catfish (perhaps an Otocinclus) or two for clean-up duties.