Scissortail darts are social with their own kind they should be fine and will probably group up upon seeing each other. The purples are a no go they will pair up and fight anything else that looks the same. Same goes for most other "firefish" also dont mix them. Its a lot of fun watching their interaction with each other. I have been trying to get a larger group of them but getting them healthy has been a challenge and they are very jumpy especially at first. Any large or aggressive fish may cause them to bolt so make sure to have a lid and your overflow covered. Also until they are used to you approaching the tank they may do the same. The two I have left will eat from my hand now. I started with 1 got 6 more into QT and only 3 of those survived, 1 jumped into the overflow when my tang charged them (he does not attack but he likes everyone to know its his tank) unfortunately I didnt have it covered. The three lived happily for about a year and I lost power and didnt have a backup power source for 16 hrs (stupid me), I lost one of the three in that. I think for my 180 I will get 10 or so from DR reef qt'd hopefully I will have better luck with that. But yes make sure everything is covered and they are healthy they are pretty hardy once in a healthy tank and acclimated to it. They usually bolt for their chosen rock once acclimated but can bolt straight up and out.
