Help I’ve lost 5 goldfish in about two weeks

[Abbyabby356]

I’ve lost five goldfish in about two weeks they all start laying on the bottom struggling to breathe they have an air stone though. They won’t eat and then they start flopping around on the bottom. And won’t get up and swim. They also have white poop. And a tiny bit of fin tearing. The water parameters are exactly where they are supposed to be. I’ve tried paragaurd, melafix, prazipro. And I use aquarium salt every time I water change. 

[koko]

Please copy & paste the following form and fill it out to the best of your ability when requesting help for Goldfish Problems:

 

Test Results for the Following:

 Ammonia Level(Tank)

 Nitrite Level(Tank)

 Nitrate level(Tank)

 Ammonia Level(Tap)

 Nitrite Level(Tap)

 Nitrate level(Tap)

 Ph Level, Tank (If possible, KH, GH and chloramines)

 Ph Level, Tap (If possible, KH, GH and chloramines)

Other Required Info:

 Brand of test-kit used and whether strips or drops?

 Water temperature?

 Tank size (how many gals.) and how long has it been running?

 What is the name and "size of the filter"(s)?

 How often do you change the water and how much?

 How many days ago was the last water change and how much did you change?

 How many fish in the tank and their size?

 What kind of water additives or conditioners?

 What do you feed your fish and how often?

 Any new fish added to the tank?

 Any medications added to the tank?

 List entire medication/treatment history for fish and tank.Please include salt, Prazi, PP, etc and the approximate time and duration of treatment.

 Any unusual findings on the fish such as "grains of salt," bloody streaks, frayed fins or fungus?

 Any unusual behavior like staying at the bottom, not eating, etc.?

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