Water softener

[PlantedGourami]

Hi, so I have a water softener that causes my gh to be very low (2-3) and was wondering if there was a way to add it for snails without harming my fish? They're all softwater but used to high ph and kh (14 kh, 7.8 ph) but I'm wondering if raising GH would stress them
I was also planning to use seiryu stone for a rescape, will that raise gh and kh or just gh?
I'm not able to bypass the water softener because I'm on the second floor and the high GH shift would probably stress my fish
I have black phantom tetras and leopard/false juhli corydoras

Edit: unsoftened water is 17 kh 22 gh 7.8-8 ph

 

[Cyberfish]

Seriyu stone will raise the kh as well.

As long as you slowly transition to a higher gh and don't do it immediately, your fish will most likely be fine.

 

[PlantedGourami]

Seriyu stone will raise the kh as well.

As long as you slowly transition to a higher gh and don't do it immediately, your fish will most likely be fine.

Should I use seachem equilibrium? I'm planning to only raise it to 6 gh or so
And how do I keep the GH stable after changing it, do I add to the water change water? I do 25% (5 gallon) water changes weekly

Also can I ever keep shrimp or would the softener water kill them?