How odd to buy fish that you don't intend to keep. Do other people do this?
I get too attached to my fish. I wanted to rehome some to get some neons but couldn't choose between them! Still working on getting that second tank but we just got a kitten so I'll probably have to wait 'til christmas!!
I would imagine 7.3 is fine but I have never kept or researched this fish so I'd see what Angel Lady says.
Not helpful I know but I had to respond as I just don't get the thing about getting rid of fish, mine even have names (all of them, including the black widows)!