Which fish to move for new male betta

[rasbora]

I have two tanks with the following size and fishes:

First tank : 75 gallon
3 common cory
9 panda cory
3 platy
3 gouramy
4 prastila (?) tetra
3 unknown tetra
9 rasbora espei
11 harlequin rasbora
4 male guppy
6 red nose tetra
10 amanos shrimp
1 red cherry shrimp

Second tank : 15 gallon tank
6 neon tetra
2 female guppy
1 male guppy
1 female guppy fry
5 amano shrimp

I am considering to buy one male betta.

My plan:
Return neon tetra, unknown tetra, 3 male guppy and platy to LFS. Move all guppy to 75 tank. Move 9 harlequin rasbora and 3 common cory to 15 tank and put the betta to 15 tank.

Any other ideas ?

If I want to put the betta in 75 tank, which fish should I move from current condition ?

[bruinsbro1997]

I think the fifteen gallon tank sounds like a good place to start for him first before you add him to your 75 gallon to see how he does with other fish.

If you wanted to move him to the 75 I'd get rid of the guppies only because I have seen bettas attack guppies because they look very similar. Many would also say remove the gouramis but in that size of a tank it shouldn't be a problem. IME my betta and honey DG get along fine.

[rasbora]

Fish moved. A new male betta is in 15 gallon now with 8 rasboras (mixed), 3 common cories and 5 amano shrimp. So far so good.