I'm pretty sure its the same rock, but they might have two styles, base and flat. I'm biased towards reefcleaners b/c John personally e-mails you, and his products (both CUC and rock) are awesome. I bought a 50lb box to replace the LR in my 90, and there's no way I can get another 50lbs of that stuff in there, it's so porous and lightweight. 50lbs would be more than enough for your 65gal. Oh, and you can write in the note section what size rocks you want, and he'll hand pick them out for you.