They will adapt to just about any pH, temp should be around 78*F, KH and GH don't really matter. You need to keep them with NON agressive or excitable fish. Beyond that I can't really tell you what your problem with them is. I need to know a few things about your tank as I have asked for before. Here is a list of things that will help me figure out what's going on hopefully....
tank size:
tank mates:
lots of hidding places (y/n)
how long have you had the tank:
have you cycled it:
are they small or full grown:
how much and how often do you do water changes:
in what order did you introduce the fish to the tank:
How long have you been trying to stock your tank(days, weeks, months):
do you have live plants:
if you have live plants do you do CO2:
how long have you had the gouramies adn other fish:
I think that'll do it for now I may have more later. Rose