Need Ideas

[HUFC]

I currently have a 75l tank with 4 mollies and 1 betta.

If i got about 9 neon tetras would i be aboe to add anything else

Also are there any snails that wont overrun my tank by breeding

 

[Plecc]

I wouldn't like to say without knowing what filtration you have.
What about getting a bottom feeder or two, they will help keep the tank clean and are much more interesting than snails.
a small pleco or a little pack of corydoras