I’ve also experimented with a few unconventional items in my tanks, always making sure safety comes first. Food-safe ceramics can be great—clean coffee mugs or small bowls (no glazes or painted surfaces!) become instant shelters for shy fish. I’ve also used glass jars on their sides to create cave-like retreats, and the fish seem to appreciate the added territory.
Another idea is to use aquarium-safe netting framed with plastic embroidery hoops. Submerged, this gentle barrier creates “plant corrals” to keep floaters or aggressive growers from taking over the surface. It also helps fry hide from bigger tankmates.
For larger fish, wide PVC pipe sections—cut and sanded for smoothness—work well as tunnels and hideouts. I leave these bare or wrap them in moss using cotton thread, which lets them blend in while still offering utility.
When using anything not specifically made for aquariums, I triple-check it’s non-toxic, free of sharp edges, and hasn’t been exposed to soaps or chemicals. If I’m unsure, I leave it out. Functionality and the fishes’ safety always come before looks. Small, carefully chosen non-traditional items really can add new enrichment and interest to an aquarium setup.