If my guppy fish tank water is very soft will that hurt my guppies and their fry?

[Jalen]

And my ph is 8.4 i know that is too high!!

But what does that mean for the fishs if the ph is 8.4
23 gallons

 

[kyle c]

wow they will die they need 6.5 to 7.5 in ph
and how big is their tank???