The red hump clade (crassilabris, steindachneri, and pelligrini) are some of the most adaptable Geophagines.
They inhabit varying water types, and are from west and north of the Andes, and north into Panama. G. crassilabris from Panama, can be found in mineral rich, alkaline water with a pH of 8.2 and above, so they don't require some of the more stringent soft water parameters some Amazonian Geophagine need.
I had some steindachneri start to spawn at only @ 2".
But males can be hard on females, especially in if housed small tanks, despite their small size
I'm hoping to pick up some crassilabris soon, my tanks average a pH of 8.2 and above.