“Why are my fish swimming at the top of the tank?” I shouted one night.
I had recently gotten my fish tank “cycled” and it was all pretty much for my blue crayfish. Of course, my crayfish hobby soon blossomed into a partial fish hobby as well.
I’d read nightmare stories online about people with new aquariums and semi-tanks having total die-offs of their fish. And that’s just horrible, to say the least.
I wasn’t going to let this happen to me, but it almost did.
Below I’m going to tell you my story of what happened, and what I did to fix my toxic aquarium and ultimately save my fish.
The Story of My Fish Who Swam at the Top of the Tank
I’d had my tank for about a month. I thought my tank was properly cycled and I was out of the woods as far as having any major problems.
I thought that everything was going as planned.
I listened to what the guys at the pet shop told me to do.
I had cycled the tank with a couple of feeder fish, fish food and some daily bacteria for seven days before I put my crayfish into the tank. And with the okay from the pet store guys (Pet Shop Boys?), I also added two more fish.
I added a red-tailed shark and a hatchet fish.
Since the feeder fish had died off during cycling, this gave me two fish and a crayfish in my 10-gallon tank. Big deal. I thought I could surely add more to my tank.
The Pet Store Guys Said it was Okay to Add More…
I liked my blue crayfish so much I thought it would be nice to have another crayfish. So I went back to the pet store and asked about getting another crayfish.
I told them the status of my tank and they gladly gave me or said I would be okay with getting another crayfish.
Wrong! Never put two crayfish in a 10-gallon tank. They’ll kill each other, first off.
So anyway, I bought a white crayfish, a molly and two tiger barbs (see “Blue Crayfish Tank Mates“).
Fish Tank was Good for Two Days
After adding a few tank mates to the fish tank, things got really interesting. The white crayfish chased the fish much more than the blue crayfish, and the blue crayfish and he even had a couple of “spats.”
But at any rate, everything in the tank seemed to be going well, for two days anyway.
Hurry! Get on Google and Search “Why are My Fish Swimming at the Top of the Tank?”
Then it happened. Somehow the universe, or more like biology, was not going to allow the sheer awesomeness of my fish and fish tank to last, however.
One evening, while sitting in the very place where I am sitting now, I turned and looked back at my aquarium—and ALL of my fish were swimming at the top of the tank.
It was obvious, things weren’t good.
My hatchet fish was hanging on for dear life. The other guys were hanging in but definitely needed some emergency intervention.
So I then turned to Google and searched, “Why are my fish swimming at the top of the tank… and looking near death, dammit?”
The Reason Why my Fish were Swimming at the Top of the Tank
What I learned was this: My tank was overloaded with ammonia from way too many fish. I had a toxic aquarium.
Ammonia is toxic for fish and it was sitting at the bottom of the fish tank.
My tank was new and the nitrogen cycle wasn’t strong enough to handle all of the fish and two crayfish, who put out lots of waste by pooping and peeing.
Oh, and I also learned that the guys at the Pet Store should not have given me the “okay” for more fish and much less another crayfish. Sheesh!
How I Fixed My Toxic Aquarium
Well, like most people do when they are having an emergency and don’t have access to any kind of professional, I went to Google, of course, to find out how I was going to save my fish. (My crayfish were fine throughout the whole ordeal.)
I searched and read article after article after article and went to every forum post I could find. However, I didn’t have much time. The ol’ hatchet looked like he needed a stretcher and an oxygen mask.
What I finally read over and over that helped me save the day was about doing a massive water change in order to fix a toxic fish aquarium (when you notice fish at the top of the tank).
But, I couldn’t do such a massive water change where I removed all of the beneficial and “good” bacteria from my tank.
So I decided to change 30% of my water in my 10-gallon tank.
I quickly took out the water and dumped it outside, conditioned an equal amount of water, made sure it was the right temp as my tank water, and SLOWLY put the water in—little by little.
Unfortunately, the hatchet fish met his end and floated to the bottom of the tank where my blue crayfish, “Bully,” grabbed him for a snack.
Within 30 minutes of my water change, my fish all started becoming re-energized. They were now moving much more. The red tail shark was darting around a little. My tiger barbs didn’t look drunk and confused. I felt like a fish EMT.
Emergency Water Change
What I learned with this experience is to watch your fish closely and act early.
I learned it’s best to have a good understanding of the current state of your water. In this case, an emergency water change was absolutely necessary and did save my fish. I also learned from this experience that you can’t always listen to the “Pet Shop Boys”.
All of the fish need a much bigger tank!