This is how I got my pair of black/white ocellarius to host. I purchased an rbta hoping they would attomatically jump in there and start hosting but nope, it didn't happen. Five months later, I tried the picture trick. I taped a pic of a maroon (couldn't find a black occelarius pic) clown hosting in a rbta up against the glass on the side of the tank that the clowns liked most and still no hosting (my female would just have a stare off with the much larger maroon clown). One night about 2 weeks later I started to get upset since I paid a decent amount of money on the rbta just to have my clowns not host in it, that I tore the pic off and threw it away. The next morning the much smaller male was hosting
. About a week or 2 later the female joined in
.
I don't think it'll work for everyone but it worked for me.