Vacuum out the uneaten food. It looks to me like he needs more hiding places. That plastic plant may tear up his fins...
I would work on water changes to get rid of all those additives. I don't think they're helping & may add to trouble.
I've never had a water softener so I'm kinda guessing about your water issues. The softener removes GH (general harness) & adds sodium (salt) instead. Your fish is a freshwater fish, it doesn't want salt at all. Can you bypass the water softener? Maybe a outdoor spigot?
I would work on water changes to get rid of all those additives. I don't think they're helping & may add to trouble.
I've never had a water softener so I'm kinda guessing about your water issues. The softener removes GH (general harness) & adds sodium (salt) instead. Your fish is a freshwater fish, it doesn't want salt at all. Can you bypass the water softener? Maybe a outdoor spigot?