I need a help...How to close open surface

Hi, I modeled it with a grasshopper pufferfish plugin and it’s open like this.
I want to make it into a closed object and print it out on a 3D printer.
I’m going to print it out 500 to 1, so it’s small, I think it’s better to close those holes instead of extrude, is there any good tips? I’d really appreciate it if you could tell me a solution to try.



Use multipipe component instead of pipe.