What should make a good eddition in my tank?

[guppy12]

I have a 20 gallon, the temperature is 79-82 degrees,30-50% PWC every week. THe filter media gets cleaned every month. The fish get fed 2-3 times a day wiith a variety of food.
My current fish-
1 male Killi fish
1 male guppy
2 albino corys
1 false juhli cory
2 kuhli loachese
2 rainbow threadfins
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Fish to add
1 female killi fish
5-10 rainbow threadfins
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Fish to take out
1male guppy

What do you guys think?

 

[plecoperson]

I would add more rainbows!

Very nice tank, by the way--

 

[tropicfishman]

Go for the rainbows!!! the one lone guppy would seem out of place to me anyways lol