I want to make a cave for my bn pleco in the 29 gal tank. I have an assortment of larger and smaller river rocks I thought I could glue together with aquarium selant to make the cave. How large of a cave would an adult male bn pleco need? Size of the bottom of the cave, height, and size of entryway. Oh, also do ya think a more round base or oblongish shape would be best?

I have little coconut huts in my other tanks for the plecos, that are essentially half the coconut with a door and a small hole in the top cut out for entrence and water flow. I am thinking perhaps a little shorter but maybe roughly the same size at the bottom of the cave would do ok. Perhaps squish the circle a bit to make it a little narrower but also a bit longer so the pleco could comfortably fit entirely within the cave?

All suggestions and reccomendations are welcome.

I think anything that a pleco can get its entire body inside of would work

I agree. I would go towards longer so the fish isn't half-in, half-out.

Good luck, and post pics of the final cave, it sounds cool!

Thanks for the input. I will probably assemble it this weekend when I have time to play with the rock arrangement for it.