Are box filters safe for kuhli loaches?

Question

What if they swim up the filter?

Answer 1

They should be okay for the most part, but when the Kuhlis become very active at night, they may make an overzealous leap into the box filter and require some rescuing... You could tie pantyhose over the intake to prevent their "escape", but it should, usually, be pretty good. For adventurous Kuhlis who love to inspect every nook and cranny, I would suggest HOB or Canister filters, but a box filter should be okay.

Soop Nazi

EDIT: I was at the fish store today, and sure enough, they had Kuhlis. They had about 10 in the tank, and 5 that decided they wanted to chill out in the filter. Maybe some very fine mesh would work to keep them out?

Answer 2

The thing about kuhli Loaches is that they will disappear into the gravel and decor of the tank. I had a bunch never saw them for years. I thought they had died. I went to change tank and during the take down found a thriving well populated Loaches society. It was surreal and kinda funny.
As I have come to understand it the filter should not bother them. More so they may be as indestructible as mollies but who would know it since they hide better than Ninja's. Hey maybe that could be a question for Ask A Ninja. " Are Kuhli Loaches Fish Ninja?"