Why Does My Fish Keep Dying in My Aquarium?

Fish can die for all sorts of reasons, but if you find that you are repeatedly losing fish one at a time, or all of your fish aren’t seeming to thrive in your tank, it is essential to troubleshoot and find out what the problem is.

Common problems include poor water conditions, overfeeding or stress, but getting to the bottom of it will ensure any new fish you purchase will be happy, healthy and content.

Below, AllPondSolutions explains three typical reasons fish keep dying and how to rectify the issue.

1. You Didn’t Properly Set Up Your Aquarium

Poor water conditions are the number one reason fish die, and it’s extremely important you have the right water, pH level, temperature, salinity and concentrations of nitrogen and ammonia, depending on the species of fish, plants or crustaceans you are keeping.

Most tanks will need Aquarium Filters that remove waste and plant particles, algae and excess food, so if you have set up the aquarium without a filter, you might find that poor water conditions kill off your fish very quickly.

2. Your Aquarium Setup Doesn’t Suit Your Fish

Fish acclimation means the fish get used to the water, and new tank syndrome can be disastrous. If the tank doesn’t have sufficient ‘good bacteria’, or you have used a freshwater setup rather than marine, for example, it will likely kill your fish.

If your fish die straight away, it means you have shocked them – and missed the fish acclimation stage, where your tank ecosystem is matured and has water conditions they are used to.

Picking up the right Cleaning Tools and testing kits can help you monitor the water and decide when it is suitable to add your fish.

We’d also recommend you make sure you are feeding the correct Fish Food since some fish prefer pellets, others flakes, and some eat from the water surface and others from the gravel. Do a little research about your selected fish species, and you'll be able to adjust the aquarium setup accordingly.

3. Your Aquarium Is Too Small

Fish Tanks come in varied sizes, and if you have very small fish species or a limited number of fish, a micro tank may be perfectly adequate. However, if the conditions are cramped, you may find that overfeeding causes a decline in water condition, or there simply isn’t enough space to keep your fish healthy.

One small fish for every gallon of water should be the starting point, so if you have too many fish or too small a tank, it's advisable you either reduce the number of fish or invest in a larger aquarium habitat.