Your fish keep dying but water is fine, then it is not a simple problem that can be ignored. If you have tested your water using a “water testing kit” and find that all necessary numbers are just fine, then obviously it is something else that is causing all the deaths.

Reason for fish dying in you tank are many and can be hard to identify. One of the most important reasons for deaths is stress and if you pay attention to several probable reasons why fish are under stress, you’ll be able to get to the root cause of deaths.

If all water parameters in your tank are good after making tests then the next step is to find out why your fish are still under stress. If stress is not treated, it leads to diseases and these can lead to death. It is not that all your fish will die in one day, but most of the times they start to die one by one.

In a fish tank there are three factors that decide health of a fish.

  1. Water chemistry
  2. Tank environment
  3. Maintenance

If you find that after testing water all the parameters are intact then the other two must be examined closely so that if there are any loopholes, you can correct them and save precious life of fish.

The word “tank environment” has a big meaning and contains lots of things that many new fish keepers miss out and the results can be dangerous. Let’s have a closer look at what “environment” in a fish tank really means.

The truth is if your tank maintenance schedule is strictly followed then water chemistry will remain in permissible and safe levels and this can be easily rectified using water testing kits.

However if fish in your tank are dying even after following strict cleaning and maintenance schedule then it is necessary to closely examine the tank “environment” which includes a variety of things.

Let’s have a look at some of these.

1) Choosing wrong tank mates

If water chemistry is all good in your tank and fish are still dying then it is time to examine your rank mates and fish compatibility. Not all fish can stay together like friends. When you chose fish for your tank you must have a clear idea of which species will go well with each other. If you don’t follow these rules you’ll see fights leading to death as well. Most people who are new to this hobby simply buy fish because they look beautiful and are colorful, but don’t forget fish compatibility.

2) Male to female ratio

Many new fish tank owners ignore this point completely, but is equally important like choosing tank mates. If you have too many male in the tank then they will fight for the single female and these fights can lead to death as well. That’s why it is necessary to have 2-3 female fish foe a single male fish so that when they start chasing or fighting for mating purpose another female will distract their attention and they’ll have some options to chose from females.

3) Already sick fish

When you buy new fish from pet store it is necessary that you put them in a quarantine tank for at least 15 days and observe for any sort of visible disease or any unsuitable behavior. It’s possible that he is already sick or under stress and carries some kind of diseases with him. It should not happen that he spreads disease in your main tank. Normally fish that are in a pet store are already under stress because they are constantly changing locations from natural lake to the pet store and then to your tank. These movements put them under great stress causing to lose some immunity. Low immunity can be a cause for attracting diseases in these tiny and delicate fish.

4) Lack of enough oxygen

Fish survive on oxygen that gets dissolved in tank water at the surface level. In many tanks air pump forces outside air in the tank through a tube. This air rises above in the form of bubbles and agitates the water surface. This is where beneficial gas exchange takes place and fish survive on this dissolved oxygen.

If enough oxygen is not present in water column fish start gasping for air at the top surface of the tank. If this problem is not treated, fish go under stress and their immunity decreases attracting some kind of a disease. Stress or any sort of disease can be a reason for death in a fish tank.

5) Faulty or insufficient equipment

Many new people in this hobby underestimate the importance of having sufficient equipment to retain the minimum required balance in water chemistry.

Simply having the equipment is not enough it must handle the volume of water that is present in the tank. If you have faulty equipment then at least you must have a spare piece to take its place when the original one is not working. This requires investment of money and many people ignore this important point.

Your equipment must also have enough power to carry the load of the water volume present in the tank.

6) Location of fish tank

Yes, where you keep your fish tank is very important. Never keep your fish tank on the floor because people walk around the tank all day and this creates vibrations in the tank water. These vibrations can disturb fish and can lead to stress.

Secondly if you have other pets like a cat or dog, they are likely to put mouth in the tank and disturb the setup.

Another important point to consider when you chose location of your fish tank is the amount and direction of direct sunlight falling on tank walls. If you tank receives direct sunlight it will encourage algae growth. Algae is not bad for fish, but it makes fish tank look ugly. Algae will grow rapidly in the tank making the entire water column green.

7) Not having a quarantine tank

When you buy new fish it is necessary that you put him in a quarantine tank first for at least 15 days and observe for some physical symptoms of diseases. Most of the times fish at pet store are under great stress and are low in their immunity. Such fish with low immunity are likely to have some diseases already in them.

If you put these fish directly in your tank, then chances of spreading diseases to other fish greatly increases. So even if your water chemistry is intact newly introduced fish can spread the disease through them to other fish and make the entire setup sick.

Fish Keep Dying but Water is Fine