The Haunted Aquarium of DEATH

I swear, it must be a miracle that my kids and four-legged pets haven't kicked the bucket under my care. Because apparently, I'm not all that great at taking care of stuff: I can't even keep a fish alive. This morning when I woke up, our last shubunkin goldfish was belly-up at the top of the tank. The second one in three days. Ugh.

Actually, I'm pretty sure I'm not the guilty party. I mean, my houseplants are thriving, so you'd think if I were that negligent I'd have killed them off too. Right? The thing is, I believe our fish tank to be ... *cue scary music* ... haunted.

Why do I say that? Because every. single. fish we put in there ends up dead within two weeks, despite our best efforts.  I'm not exaggerating when I say that we've probably had fifty fish in our tank since we bought it a couple years ago. All different types. At first I thought maybe we were choosing fish that were too high-maintenance, so we switched to hardier goldfish - but now, like thirty-plus "hardy" goldfish later, I'm fairly certain it has something to do with the tank.

And that really pisses me off, because I do everything I can to ensure that it's sparkly-clean, and that the environment has the proper levels of everything. Between every batch of ill-fated fish, I empty the water, scrub down the tank, change the filter, and clean the gravel and plants (with a special toothbrush, y'all!). I never use cleaners, only fresh water. I refill the tank, add stuff to make tap water safe, add stuff to start the cycle of beneficial bacteria, and wait for days until the aforementioned bacteria has had time to colonize or whatever the hell it does. Every time, I re-research how to set up a tank properly, and do it to the letter. The fish are never overcrowded. And it's not like I forget to feed them.

So the only answer? Paranormal activity of the aquatic kind. It has to be, like, the fish version of The Grudge where the ghosts kill people. Although in this case, it's some goldfishy ghost peeping openmouthed with its sunken eye sockets from behind a plant or something, and the new fish just can't take it and they, like, have little tiny heart attacks. Or something.

Or not.

I just don't remember it being this hard when I got my first fish tank, three thousand years ago in the '80s. I seriously think my mom just filled the tank with tap water and plopped the goldfish in and that was it - and those things actually outgrew the tank!

So what's the fatal flaw? Is it something I'm doing wrong, or is my tank cursed horror-movie-style?