Help! Dead fish every day.

[mbsqw1d]

OMG. You are right! I did use Metroplex for that. I’m old and crazy. I had some from a year ago and tried it here. It did work. Geeze, I worry about myself sometimes.

We'll let you off, given the amount of tanks you have setup I reckon I'd be the same!

 

[Sandy's fish and botia]

Did you add any plants? If they had pesticides it could account for the symptoms you are describing and not be obvious in parameters. Or as @NCaquatics points out, chemicals in your hands or aquarium cleaning items.

If I've learned anything in these years from running very large retail fish, LFS. Everyone immediately let's the pleco of the hook and after losing more fish, you find the pleco IS the problem. They will get excited for no apparent reasons and fly around the tank at night slamming all aquatic life in its path. The reason I say this is I have them run straight into decorations , drop instantly, and occasionally not get up! In this case with a variety of unexplained deaths, with the red tail could be simple internal bleeding from being slammed by another fish. Now that I seem to be spoiling the reputation of certain species, let's turn to another "clean-up" fish. The Siamese Algae eater. Came home after being out all day and find your algae eater sucking the scales off of my largest and most favorite fancy calico she bunk in. Within an hour home she had to be euthanized. I saw the algae eater hanging around the back side of the Callie but as I lit the tank I realized what happened. I was in the process of moving the Callie to a display tank with a stopover, for a few days "qt" just to be safe. It was just her and the dreadful algae eater in a 29gal tank. Just beware of the quiet ones.

 

[Gypsum]

Yeah, I've had this problem with raphael cats and Sandy's Fish makes a very good point that explains a lot. I've had several species of small corys in that tank, it's gone reliably wrong with any corydoras smaller than adult aeneus. Big corys are doing fine. The raphs race around the tank, bowling over everything in their path. Any little cory who didn't get out of the way would go flying, but the raphs will swerve around the CW045s. Those things are tanks. Even if the raphaels weren't actively hunting small corys (and I would not put that past them), it's possible that the corys could have been injured by large, armored catfish careening into them at speed.