Aquarium gravel sounds like a fun twist—never would’ve crossed my mind either. I’ve tried rice before, and while it does hold heat pretty well, it also tends to get a bit... funky after a while. Moisture sneaks in somehow, and suddenly your cozy insulation smells like dinner gone wrong. Sand’s decent, but heavy as heck and a pain if you ever need to shift things around.
Honestly, I think the gravel might be onto something. Even if it’s not the absolute best insulator, it’s probably decent enough, and the color factor alone might make it worth the slight trade-off. Plus, if you ever have guests over, imagine their faces when you casually mention your walls are filled with aquarium gravel—instant conversation starter right there. Either way, kudos for creativity. Sometimes the quirky solutions end up being the best ones.
Aquarium gravel's definitely creative, but I'd be cautious about moisture buildup. Gravel doesn't absorb moisture, so condensation could become an issue. Maybe consider adding a breathable barrier or vapor retarder to keep things dry inside? Just something to think about...
