What sort of filter do you have running and what is it's GPH (Gal per hour) capacity?
As it is you are pretty well at capacity IMO, others may disagree.
If I remember correctly Kuhli loaches like to be in larger groups... Someone may have to correct me on that though...... So if you did want to add any more it would be best to be loaches, but as I said, IMO you're dancing around fully stocked so to speak.
its the Whisper i20, and it does the job perfectly!
I read 3 is a good group, but i may get 1 or 2 more, since thye have sucj low bio loads. Could i possibly fit a small group of neons and a guppy?