Betta fins curling pretty badly

[Fishlegend]

Me: I think that's all.
The friend want some more salt
Me: might as well It cures everything
The friend: that's! my boy!

 

[Fishlegend]

Lava rock

The lava rock could definitely scrape the betts if you what it for bacteria surface just putt under your other substrate so your betts doesn't scrape himself but the bacteria still has lava rock