So after the great fish die-off last week, we went back to the store on Sunday for 3 more fish. We agreed not to name them until we saw if they survived. This time we carefully did not put any of the store water into our tank. We got them safely in, and this time I was on top of testing. And wouldn’t you know, the ammonia in the water spiked almost immediately!

We fought the ammonia frenetically. Added bacteria, ammonia-locking chemicals, and changed water like mad. At night, I threw in an emergency ammonia tablet, hoping some of the fish would survive the night.

Miraculously, all three survived the night, and I changed out water immediately that morning. But only 2 of the 3 fish ate any of the food I put in. The smallest was lethargic, hiding in corners. We sensed that this one was not going to make it—and we were right. By mid-afternoon, fish #12 had died. Daughter shed a few tears: “He was a good listener. He would sit there and listen while I talked.” She told me that if he had lived, he was going to be the next in the long line of Seashells we’ve had.

The other 2 fish seemed okay, swimming around rather vigorously when the ammonia levels dropped after a water change. I tested the water and changed water every 2 hours the entire day. The ammonia levels dropped and stayed dropped, although not quite perfect yet. Then the second night was upon us, and I used another emergency tablet overnight.

The next morning (Tuesday), both fish were still alive, and the ammonia levels had dropped a bit more overnight. However, one of the fish was acting badly. Not energetic anymore—and his mouth looked white. He did not eat, even when the food particles floated right past him. This fish already had slight tail-rot, so against my own advice I had started calling him Holey. Holey’s behavior deteriorated throughout the day. Then, in late afternoon, Holey died—and my daughter saw it happen.

My daughter was distraught. “He was a trooper. He tried so hard to stay with me, because he knew I wanted him to. He was swimming sideways. I sang to him, because I knew he wanted me to.” She insisted that his name was not Holey, but Holy “without the e” because it suited his personality. Many tears were shed over this fish and witnessing his demise.

I felt bad about Holy because I wonder if I had been more aggressive with the medicine that protects against tail rot and mouth fungus if I could have saved him. We have had fish survive tail rot before, but we’ve never had mouth fungus. I realized belatedly that the first fish had also had that crazy white mouth before its death. I had put the medicine in the water, but I know I missed a few times. If I had been aggressive with it, perhaps Holy would not have gotten the mouth fungus, since he was fine the day prior. But hindsight is 20-20, and I will never know the answer to my wondering.

So that left us with fish #14, who my daughter named Zippy. “Zippy comforted Holy. He’s a kind, good fish.”

Today is Wednesday, and I have tested the water every 2 hours. The ammonia has stabilized at a good level, and I have not changed water as frequently. Zippy had been scratching himself against things, indicating his skin was irritated from the ammonia. I added lots of a liquid that sooths and heals the slime coat. He stopped scratching a few hours later and has been swimming around all levels of the tank (they stick to the top when ammonia is high), so that seems good. Although he did not eat when I fed his this morning, I caught him grazing on the moss ball and algae later in the day, and he gobbled up a flake of food knocked loose when I changed the water.

As of this writing, he seems happy, and his mouth is not white. I have been crashing the tank with the medicine, as well as the ammonia detoxifier and nitrifying bacteria. It seems stable. We shall see if Zippy escapes the mouth fungus scourge.

Fingers crossed for Zippy.

Those of you who have followed my blog for a while know we have had quite a few adventures in fish-keeping. We have a small 5-gallon tank, and have kept about 3 guppies at a time in there, give or take a few dying. We have had 8 guppies so far, and the last one died just before the coronavirus lockdown started. So our tank has been empty a long time.

Because of that, it took a while to get the tank properly cycled and safe for new fish. Finally, after about 8 months, the water tested perfectly for multiple days, and we went and got fish #9, 10, and 11. My daughter was very excited to have friends in her tank again! She named them Moonlight, Starlight, and MiniSeashell 2.

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We got them home, popped them in the tank…and immediately knew there was a problem. Starlight was acting weird, “vertical hanging”, which we have seen before and never bodes well. Sure enough, he died within the hour. The others seemed okay, so we went downstairs to watch a movie. When we came back up, the other two were dead.

My daughter was upset to lose all her fish within a few hours, and I was baffled. Our water was perfect, what could the problem have been? I decided they all must have been sick with something from the store, because what else could it be?

The next morning, I changed out about 2 gallons of water, put in fresh water, as I always do when there has been a fish death in the tank. A few hours later, I tested the water, since I was planning to buy more fish that day to try again.

The mystery was unexpectedly solved.

Ammonia is deadly to fish—they suffocate. My tank water the day before (and several days prior) had tested at 0, both at home and at the store. That morning, it tested at 2.0 ammonia. That’s AFTER I had changed out almost half the tank, so it had probably been closer to 4.0. Deadly.

The only place it could have come from was the store’s water. Those poor fish had already been poisoned before we bought them. If I had not dumped that water into our tank, at least 2 of them may have recovered. But I didn’t know. It never occurred to me that the store’s water might be toxic. The fish never stood a chance.

I know better now. Once again I am cycling my tank to get the water fit for fish. This time, no water from the store will enter my tank. And hopefully the fish won’t be poisoned before we even get them home.