I recently ordered from both for my tanks and that is a matter of opinion.
Rock from the gulf had lesser starlet corals along with other stuff. The rock was loaded with life.
Rock from KP had layers on layers of coraline, macro and some curlyque nems. It was also full of life.
Both had clams, numerous types of bivalves, urchins, pistol shrimps and crabs.
No mantis or crazy worms from either.
the difference in the 2 has to be where they mined the rock from. KP is lighter and more porous, while glr is a little more dense. Still porous, but heavier rock.
With that said, fiji rock that I have is mixed. I even have one piece that has geodes/crystals in it lol. That doesn’t worry me, as years ago, that rock was taken from the edge of reefs. Who knows how long it had been there. So not worried about anything leaching. If it would have, it would have done it by now.
But again, how it looks is an option of what look you like. If you want corals, go with rock from the gulf. If you want coraline and macros, go KP. Both have the same critters or chance of the same critters.
Side note: I believe rock in the gulf is from a more stable tide height area (in relation to flow and height). KP may be a little shallower and experience more tidal flow. This could could explain the difference in things that grow on the rock. I know diving 30-50’ in the gulf is a lot different that 30-50’ in the keys. Gulf I use less gas and energy during tide changes. Keys takes a little more gas and energy to hold a spot. Both still better than diving the Atlantic side of Florida for ease of diving lol.
