minimum size for clown loaches

I did a search, but I was having a hard time

I have 5 in a 180g, but I will most likely downsize eventually. I would even like to maybe get as many as 3 more clowns...so, assuming there was little else in the tank with them (like maybe a small pleco and a small school of some sort of schooling fish), what would you all recommend as the minimum?

Thanks

I was guessing 90 or 120 would be the minimum, but I wanted to hear what some of you thought . And I am looking to downsize eventually to a smaller volume. My set up right now is a 6x2x2 on a 10 foot long stand, so I could use the extra room and a bit less maintenance time.