Thanks for taking the time to respond. I did use dry rock when I set up the tank wanting to avoid hitch hikers. Also, I lost the fox face, both banggi cardinals and the gobi. All over one day. Two clowns remain.sorry. Feels bad man.
It’s so hard to say…did you just lose the foxface or other fish too? You only mention finding that one? Foxface IME are skittish. A 75g feels a bit cramped and it may have been stress got to them- especially after a cleaning. These fish can be less hardy than some others like clowns, gobies, etc.
There are certain individuals here who will absolutely immediately jump in with “oh, your fish died? It’s because you didn’t follow this 45 step, 60 days acclimation guide I wrote.” I don’t think they’re wrong, however….
I’m not sure that’s practical for the average aquarist running an enthusiast-sized tank with space limitations. I also have a local store that is reputable and quarantines their fish for you in a professional and tested manner. You pay a premium in exchange for not doing it yourself. There are also online stores with great reputations that quarantine for you.
Illness can exist in your tank, just like in the air around you. Not every cold you catch will present with symptoms. The same can go for fish. My toddler coughs in my face when I’m well rested and not stressed? Might be fine. Does it after I got zero sleep the night before and I may spike a fever.
I will throw out an alternate cause- a Eunicid Worm or other predatory pest. I have personally had one that was big enough to take down a foxface hide in a 29g biocube (but no, I did not have a foxface in a biocube) I also lost some fish and my clowns were acting terrified.
A red light over the tank and a cheap time lapse camera running overnight caught him in the act. A little piece of shrimp rubberbanded on a rock to lure him out worked too. Although I had to tear down the tank to get it out and it fought me tooth and nail.
Sorry for your loss. It happens. Thank you for taking the time to try and understand why. That’s the important part.