scissortails do need to be in a larger group than that hun -
they also grow to approx 4" so you'd need a bigger tank than 10 gallons - most recommendations min of 20-25 gallons for them
you really need to find a smaller fish to add in there - and if its a schooling one min amounts are approx 6 for most schoolers to feel safe
o some more research and look at lots of other small fish hun then
feel free to bombard me with names of other fish to see if they're suitable
you really need nano type fish for a 10 gallon tank