10 gallon nano, 3-4wks old, started with 10lbs CaribSea Life Rock and 10lbs Ocean Direct sand. My LFS won't sell me live rock on account of the pieces won't fit in my tank (some of them definitely would have, but they wouldn't hear it). They won't sell me live sand either for reasons they won't really specify. I only want some rubble or something to seed the tank with so I really can't justify the cost of online purchase+shipping. Wondering what I can do to get some biodiversity going as the next closest LFS is a ~4hr round trip on a good traffic day