I'd say they'll kill the ottos if you don't move them. Tiger barbs and peaceful fish that tend to stand still is a no no. The clown loaches on their own won't touch the ottos but they are copy cats. I've heard about killer clown loaches once before but it's extremely rare. My loaches haven't managed to wipe out the cherry shrimp population yet and ignore average fry the length of my nail and they can certainly fit their mouths.
My tiger barbs just spawned and I had to remove the female as well as the ottos it was a feeding frenzy..... Anything that moved was being inhaled and she was being lifted out of the water by loaches and barbs, it was like a fight over a pez dispenser.
My tiger barbs just spawned and I had to remove the female as well as the ottos it was a feeding frenzy..... Anything that moved was being inhaled and she was being lifted out of the water by loaches and barbs, it was like a fight over a pez dispenser.