If you are hoping for line breeding of the same strain, you need to separate the turks from the others, Then, see what happens. A 29g or better 55g is enough. They might like a change of scenery or some alone time to see where it might go. You can always put 1 back in their former tank & try again with another possible partner. Mixed strains may produce fry but they'll not likely be as pretty as they might.
I raised young 2 inch discus but it wasn't until I sold them to a friend that they paired up in his tank. Before that they were just sparing siblings...but all the same strain with possible different parents.
I had tried to guess sexes by looks & behavior before I rehomed them. I was wrong pretty much all the time, lol.