Quick dying fish

[Parrothead]

First off, sorry for not having pictures, I have a 110 Gallon tank that has been set up and running for 9 months. I started out with 16 cichlids that we’re all about one inch, as time went by they started dying off one after another with no apparent reason. The bigger they got the more aggressive they got, the last month they started looking like their scales were turning outward and sort of fuzzy. As of last night the healthiest looking fish which was the bully of the tank started looking the same way and the last four fish dyed overnight. My question is what should I do before buying more fish, I treated it for fin and scale rot, how long before I should buy more fish? I just changed 50% of the water and the carbon before they all got this fuzzy scale and dyed. Did I do something wrong?

 

[Parrothead]

First off, sorry for not having pictures, I have a 110 Gallon tank that has been set up and running for 9 months. I started out with 16 cichlids that we’re all about one inch, as time went by they started dying off one after another with no apparent reason. The bigger they got the more aggressive they got, the last month they started looking like their scales were turning outward and sort of fuzzy. As of last night the healthiest looking fish which was the bully of the tank started looking the same way and the last four fish dyed overnight. My question is what should I do before buying more fish, I treated it for fin and scale rot, how long before I should buy more fish? I just changed 50% of the water and the carbon before they all got this fuzzy scale and dyed. Did I do something wrong?

After looking up fish diseases it looks like fungus, now to get rid of it.