Are you sure your Midas is a male?
8 months & only 5" that's quite small.
I have a female who is about 6-8", I rescued her so I don't know how old she is my guess would be a few years old.
I kept my male alone for about 6 months, he doesn't like any fish near his size or bigger.
I added in a few of my hybrids as dithers & he seem ok with them.(so far)
He doesn't like my female too much & will not tolerate her being in his tank.
My female used to be in a community tank(before I got her) but she goes insane @ the sight of another fish, she is alone & being conditioned to spawn again.
8 months & only 5" that's quite small.
I have a female who is about 6-8", I rescued her so I don't know how old she is my guess would be a few years old.
I kept my male alone for about 6 months, he doesn't like any fish near his size or bigger.
I added in a few of my hybrids as dithers & he seem ok with them.(so far)
He doesn't like my female too much & will not tolerate her being in his tank.
My female used to be in a community tank(before I got her) but she goes insane @ the sight of another fish, she is alone & being conditioned to spawn again.
, i had 10 tiger barbs which he killed them all and had to remove my adult male bristlenose before he killed that as well 
