My Mollies Are Dying: What Do I Do?
Mollies are among the more popular community fish found in freshwater aquariums, but they are also very sensitive to poor water conditions. If you have had a few molly fatalities, then it is time to find out why and how to prevent it from happening again.
Mollies are very sensitive to poor water conditions. Most of the time, death is caused by unidentified (or ignored) water quality issues like ammonia spikes or pH swings. Other problems include diseases like velvet, fungus, or even an existing bacterial infection.
And since mollies are live-bearers, it is important to keep vets or other medications on hand if your fish fall sick. Mollies are also very sensitive to nitrates, so you must make regular water changes.
The recommended percentage of the aquarium water to change out varies depending on the aquarium’s condition. Still, if your mollies are dying off for no apparent reason, it would be a good idea to change the percentage of the water.
If you suspect your mollies are suffering from an illness, the first thing to do is quarantine them from the other fish. Since they can catch diseases from each other, they should stay away from the group for at least two weeks to see if they will recover.
If you have more than one fish tank, it is a good idea not to put the new mollies in the main aquarium while their immune system builds up its defenses against diseases. Instead, please place them in a cycled bucket with some of the old water from your tank and feed them a small amount of food every morning to keep them active.
After two weeks of quarantine, if your mollies are still suffering from some illness, then it’s time to let the vet know so that they can start doing some tests on them. The most commonly used test for aquarium fish is a quick bacterial culture called a gram stain because it is relatively inexpensive compared to other types of tests.
If the bacterial culture results show infection, it would be best to treat with antibiotics like ampicillin. This process will help you kill off the bacteria while minimizing damage to your mollies’ immune system. If you chose this route, make sure to change out at least half of the water a few days before you add the medications to prevent some of the bacteria from getting into your tank.
If the gram stain doesn’t show any infection, then it is probably time to focus on what caused them to get sick in the first place. One of the most common reasons why mollies fall ill or die is ammonia spikes due to a lack of cleaning. Ammonia is one of the biggest stressors to regular aquarium fish, so it will kill off weaker mollies fast if you don’t monitor your tanks often enough.
Ammonia starts from rotting food and fish waste trapped in tank crevices and substrates. Cleaning these areas will help prevent ammonia spikes. Wiping off the substrate with some paper towels is sufficient, but removing the gravel and rinsing it in a bucket is even better if you don’t have time to vacuum everything.
If your mollies are suffering from an existing bacterial infection, changing out the water is another good thing to do. Here, it would help if you changed out about half of the water to prevent infecting your other fish. If you don’t have time to change the whole tank, do enough until you can get some medications or bring your fish to a vet.
After figuring out what is causing or preventing your mollies from getting sick, the next thing to do is put preventative measures in place so that it doesn’t happen again. The best way to keep your mollies healthy is by maintaining their water condition through regular testing and regular water changes if necessary.