Fish dying

[Brucej]

Hi all, I would be grateful for any thoughts. Have lost about 5 fish over past month. Fresh water tank, temp 27celsius. All water parameters seem ok. Ammonia, nitrates and nitrite all show zero/ minimal.
Ph 7.4
I tried salt, and had no deaths for about 10 days, so thought it had cleared...

Latest death was one of my Angel's. My wife took a photo before disposing, and looks like some sort of ulcer / hole behind the eye.
Any thoughts / suggestions

 

[Potluck]

Nitrate shouldn't be zero, it can be if the tanks heavily planted but my tanks heavily planted and I never drop below 5ppm (even dosing 20 ppm weekly) , when you say seem Okay ammonia should he absolute zero, nitrate should be zero nitrate 5-20ppm, don't confuse nitrite (ite) with nitrate (ate), nitrite is deadly at very small ppm where as nitrate is the biproduct of ammonia and nitrite and isn't as harmful I stopped worrying about nitrAte a long time ago, you should be using a liquid test kit to test your water as test strips are innacurate, what you're describing sounds like Hexamita (AKA Hold-In-The-Head Disease)

It's a parasite, you'll need metroplex (medication) if you can get it where you live, and here's the steps to treat, Step 1)*Quarantine the infected Angelfish in*a hospital aquarium setting*or*a suitable aquarium setting, but along with the normal diet, feed the Angelfish spinach.
Step 2)*Every 2 hours, increase the water temperature of the aquarium 1-2 degrees until it reaches 90°F (32°C).
Step 3)*Treat the aquarium with MetroPlex.


I'm not 100% sure if that's what this is, hopefully someone more experienced can come along to clarify.

 

[King Fisher]

The fins were tattered as well. I'd guess you had a bacterial infection. If this happens again, dose Kanaplex and Metroplex at the same time. Yes you can do this. You might double check to make sure you have a cycled tank.