Bacterial or Viral?

[cjp155]

I purchased this Loricaria on Tuesday of this week. On Friday I noticed that it was breathing rapidly even though there is more than enough oxygen (via air stone and sponge filter) in the 10 gallon quarantine it was in. It seemed to be healthy until this point. I saw it eating every day prior to Friday. Then on Sat I started to see signs of hemorrhaging. On Sun (today) it was dead. My quarantine params are perfect. I perform 75% daily water changes and maintain zero Amon, Nitri, and Nitra with a ph of 7.4. It all happened so fast and I don't know what, if anything, I could have done to prevent this death. Please review pictures below and let me know what you think. TIA

[cjp155]

[Marc van Arc]

Bacterial.
And don't blame yourself; if things go that quickly, there's hardly anything to nothing you could have done to save this fish.

[cjp155]

I don't understand why it happened so fast...

[Barbie]

You don't mention if the tank was cycled? 0 ammonia, nitrite, and nitrate is actually a sign of a NOT so healthy tank, unless it is long established. You can still be having spikes of ammonia here and there through the day. I know that my water here in Spokane is great for huge changes, but not all water supplies are. Do you have chloramines in your tap water? Septicemia (if that is what he had) is almost always because of issues with the tank. How old are your test kits? There's a list of questions at the top of the forum for posts like these. They give us information we really need to be able to give you the maximum amount of help.

Barbie

[cjp155]

It is an established quarantine tank. It has been running for over 6 months with fish in it throughout that entire period (I quarantine fish for a long time). The reason my params are so low is because I do a 75% water change every day. I check the water params every day right before my daily water change and right after using API liquid test kit -- params are never elevated. I go through a test kit approximately once a year so my test kits are never expired. Yes to chloramines (although not much at all) in my tap water. I treat the tap water with Seachem Prime. We have excellent tap water here in NYS. Also, I should note that the neon tetras in the quarantine throughout this time are doing fine.