I have 7 and kept them with clowns, yo yo, kubota, dario and zippers. They were all in a 135 with lots of cover and caves. The modesta were agressive at feeding, but mostly kept to themselves. With a large enough group they work put there own pecking order.
Modesta are found in the deep pools in the river in the dry season, they spawn with the arrival of the monsoon rains. It has been reported that the eggs are boyant and absorb water.