In my 450gal I have ~thirty 5" male peacocks, ~ten 6"-6.5" male haps, and four 5"-7" frontosa. The tank is 96"x36"x30". There is chasing among some of the peacocks but I wouldn't even call it aggression. There seems to be enough space to handle what would turn into aggression in a smaller tank. The sight breaks also help.
The four Frontosa have all grown about three inches so far with the current tank makes and seem fine in all aspects. I added nine new 2.5" Frontosa three weeks ago and they're all doing great, eating tons and I could swear they've grown some in the short time they've been in there. These new nine Frontosa came much smaller than I was expecting so I'm pleasantly surprised they're doing so well. All the Frontosa more or less hang together at the bottom while the peacocks/haps take the upper levels, but there is also a lot of mixing.
I personally wouldn't try mixing Frontosa with male peacocks in my 180gal due to the difference I believe the smaller size tank would mean. In my 180gal I've reduced the number of fish I had in there from 20 male peacocks/haps to what is currently 9, and now there is finally peace.
Besides all this I'm seeing that the more Frontosa I have the more comfortable they seem to be. In the future I'm thinking I wouldn't have less than six together, but preferable a nice sized colonly of 8-10. together.
