What should I do if Tiger Fish is suddenly blinded？

　　

What should I do if Tiger Fish is suddenly blinded？

Ten days ago, a small packet of coral sand was put in because the pH was unstable.I dont know if it has any effect?Today tiger fish suddenly blindfolded.Nothing to eat today.Yesterday it was fine.Because there are stingrays, it is not possible to put salt.There are golden arowana, stingray and tiger fish in the tank.I didnt even try to fight like this before even fighting with Arowana.Please help the gods to see how to deal with it?Thank you

　　= (Comments on alliance Sianlon Arowana Aquatic friends) =

　　Little handsome 001 Say: Dont look for other reasons, just change the water frequently.Regular water changes are good medicines, and others are poisons.
Yuyou Longing for Dragon Say: 1 Fish out
Yuyou Longing for Dragon Say: This is still the same as the old one
Yuyou defeated 006 Say:
Cant put salt.It has been warming up.Change the water tomorrow.Because you want to dry. Infatuated Dragon Lord
This is still the same as the old one
Fish Friends Say: Fished out and treated alone
In fact, there are stingrays that can be salted, do nt sprinkle it directly, it s okay, I poured it in the filter tank and melt
Gunnaca Say: Blindfolded, the water temperature increased (32 degrees or more), a small amount of water (or no water), 3-4 gentamicin injections in the king fish tank basically improved in 4-7 days
Yuyou Investment Say: Poor water quality
Yuyou smiled sadly Say: Change the water
Fish Friends woailuo001 Say: Not serious, keep the water quality, dont worry about him
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