1 front with other fish, yes not a problem. I have kept at least 1 front in a 75 for the last 20 years in mixed tanks. Sidenote: it is only of recent (last 5-10 years) that people have advocated for a bare minimum of 120g or more them. During the early 90's I knew half a dozen or so fellow aquarists who kept 3-4 fronts in a 75g with no problems. If you are going to do more than that though I would get a bigger tank.