What's the best fish to have alone?

[absolutangel04]

I think 5 neons and 4 guppies is pushing it. I think the combo of neons and guppies is fine personally. Not all tetras are fin nippers, and neons are not exactly bold. I have actually never heard of neons nipping anything.
Do you already have the 4 guppies? If so, I would honestly get stick with them or get 5 guppies.
If you want neons, I would just keep a guppy or 2, but not 4.

 

[hpNYR]

Yes i have 4 guppies at the moment what should the male fem ratio be generally?

 

[Sisserydoo]

All males unless you want babies. If you want babies, at least 2 females for every male.

 

[absolutangel04]

I agree with Sisserydoo about the gender ratios. Not many fry will survive though with that many fish unless you separate them. The females will have fry, but everybody (including the mom) will eat them.

 

[hpNYR]

You can do 3 guppies and 6 neons but not 4 guppies and 5 neons? How come?

 

[absolutangel04]

Because guppies are bigger than neons and neons all clump together to swim, but guppies don't.
The issue isn't just having 10 fish, its about catering to the behavior of the fish you want. Also, I did say (or at least should have, but sometimes I forget things so please forgive me) that even that combo is still pushing the capacity and you will have to do bunches of water changes. And I did just say that 1-2 guppies with neons is better.