Black coffee cup.
Originally Posted by AyalaCookiejar
Ah, thank you for your input! Any idea what I could do for a simple cave that is black or dark on the inside? I don't want anything too fancy, or big, just functional. I already have black gravel because my new Betta I'm getting is light colored :)
Edit: Also makes sense why my VT loves his squidward house and likes to sleep behind the black filter but never used his spongebob pineapple house or terracotta pot.
I've used coffee cups before. They're fine to use, the glaze they're painted with is food safe, which means it's safe for aquariums and fish. Just make sure it's made with WHITE CLAY. Red and brown have iron in it which will leak into the water over time. A chipped cup is fine if it's white clay.
Just make sure they're clean and either weigh them down or put them on a lego base and cover it with substrate.
Dark decorative glass, like an old drinking glass or little vase work fine and are safe. Just make sure the hole is big enough so the betta wont get stuck inside.
I've used them before. You can get a few different sizes. If you still have some laying around, they work. Might need to put a little rock inside it to keep it down. Some bettas like the small size, makes them feel safe I assume.
Some tupperwear is black or solid colored. Just cut a hole in the side for an entrance and place it upside down in the tank. Weigh it down with a rock on top or something. Makes like an igloo cave.
Small Animal Igloo
Speaking of igloos. You know those little castle igloo things marketed for mice, hamsters, and rats. Those are fish safe. Just weigh it down and make sure to remove the sticker completely.
Critter Trail Tunnels
I like these, you can get creative. Just make a simple tunnel or a complex maze type of tunnel with many exits and put it in the tank. Fish of all types like to swim through them. I've seen people make a series of tunnels and put them under gravel, making undergravel tunnels for their fish. They have the exits sitting above the gravel so there's multiple ways to get in and out. That makes vacuuming a hassle though. I'd just set it on top of the gravel.
If you have spare gravel and aquarium sealant, you can make a mixture of them together and form your own cave. This is messy though. And time consuming.