Is hardwater a problem?

I've noticed when I test the water in my 10g tank that it always shows
up as very hard. I have a rosy barb and a gold barb currently in the
tank and they seem to be doing fine. Should I add a water softener or
just leave it as it is? I intend on adding another gold and rosy in
the next few days so I want to make the changes before adding the new
fish if changes are needed.

Another question I have deals with my air pump. Should I remove it if
I want to add a few live plants to the tank??

Thanks
Val