I posted some pictures of Coolie Loaches & got chastised both for only having 3 of them ( BTW... I think treating them as shoaling or schooling fish is completely wrong ) mine are never next to each other, they are very independent... that tank also has a couple inches of polished pebbles in the bottom... I was immediately told that I had to have sand in the bottom, for them to burry into... but in reality , they are swimming in the gaps of the pebbles, just like they would in sand... they stay below the rocks, as much as they would if I had used fine sand... my loaches came in really small, & went down there right away... I didn't see them for a long time, as food trickles down between the pebbles... they have grown exceptionally fast & look completely healthy & happy right now... coming out more often, assuming they are eating more being bigger
sometimes recommendations of the minimum fish you should have, drives me crazy... I will say on my Tin Foil barbs ( which a person shouldn't have... they are too big ) they need a group to keep from going crazy... but I have only 3 ( gasp ) Denison Barbs in that tank, & for some reason, that sets people off... mine are happy & healthy, and are pretty independent, but they also occasionally school with the Tin Foils, or with the Flying Fox ( maybe the Flying Fox tries to school with the Denison's??? ) but that tank is doing really well with 5 Tin Foils, & 3 Denison's... some times fish will school with other fish of similar size & shape... some people seem to get it, with rainbow fish... 4-5 varieties will all school together... some tetras will do that, some barbs will do that... I don't think they even need to be in the same family, as long as they are similar size, shape, & demeanor, & can take at least similar water conditions... I think that telling people they need to keep groups of large numbers of the same fish, is mostly false, as long as there are others they will school with...
enough said