I have a 30 US Gallon tank. Ive read several places that they usually only get 4" in an aquarium. But Ive learned the hard way, what you read isnt always true, which is why I wanted to make a post about the loaches before I get them. I want to get a large tank in the future to get a school of Clown loaches, seeing as how the 30 I have now isnt big enough. but I wasnt sure about the yoyos