need help on my snowball shrimp

[Legit Fish]

ok im knew to this forum but i just wanted to ask is it possible to breed snowball shrimp only if you start with 6(2 females, 4males)? my shrinp just died one by one when i added them and my cpo ate one and was left with six is it possible still to breed. they are in a 15 gallon planted tank with eco complete substrate.

 

[herp_mommy]

as long as conditions are favorable, they should breed.

 

[Legit Fish]

another thing is that for some reason there is one or two that are just staying in the gravel hardly moving i saw them swim arround once or twice other then that they didnt move.... something wrong with them