A lot of people start fish keeping by chance. Most of the time, people believe that their fish died without a reason because they did not have any prior knowledge. Even though the fish died due to inexperience (lack of knowledge), people misconstrue it by thinking that the life span of a fish is normally short. So due to lack of knowledge, the misfortune repeats over and over.

There are so many problems that could be avoided with a little bit of research. Some people even give up fish keeping due to these problems. I wrote this post in hopes to help people avoid or mitigate these problems. If you have additional information to add or if there is a mistake, please let me know. 

The contents below are my summarized thoughts and opinions. I will write a detailed posts following up on these topics and link it in this post. 

Fish tank size

• Small tanks are harder to take care of and not a good environment for fish to live in.
• I recommend novice fish keepers to use a minimum tank of 25 gallons .
• You should find out how big your fish can grow and choose a tank size accordingly. 

Nitrogen Cycle

• Contamination in the water (ammonia) can decompose into less toxic substance (nitrate) through the help of beneficial bacteria.
• The build up of nitrate needs to be removed through water changes.
• Filtration cycle must be complete before putting fish into the tank. There are different methods, but for novice fish keepers, I recommend products like  Tetra Safe Start Plus.

Filtration filter

• There are a lot of different types of tank filters: sponge filters, external filters, hang on filters, etc.
• Each type has different filter capacity, cost differences and its own set of pros and cons. For novice fish keepers, I recommend sponge or hang on filters.
• You have to clean the filter frequently but cleaning it with tap water can kill the beneficial bacteria so it is recommended to clean it with tank water.

Water change

• You need to purchase a water test kit to measure the water parameters and change its water accordingly.
• Tap water contains additives that kill off beneficial bacteria so you should use a water purifier. 
• You need to make sure that the new water’s temperature is the same as the tank water’s temperature. If there is a big difference, the fish’s immune system can weaken and possibly cause death.

Temperature

• Different breeds of fish have different optimal temperatures. You should adjust the heater temperature to match your fish’s optimal temperature. 
• Most tropical fish can live in a climate of 70 to 80 degrees Fahrenheit.
• The temperature of the water is important but keeping the water at a consistent temperature is even more important.

Disease and medication

• Most fish do not catch diseases if their water parameters and temperature are stable. 
• New fish additions should be kept in quarantine in medicated water.
• If you notice your fish has a disease, you need to research what it is and calmly address the problem.
• Assuming the fish was healthy and it lives in a clean environment, most fish can last 3-7 days after onset of disease. A lot of fish die due to stress caused by rapid and excessive medication. 
• Most diseases are transmittable. Therefore, it is best practice to treat the whole tank. (excluding certain diseases and parasites)

Tank placement

• Tank placement is more important than you would think. You can not just place it anywhere you think looks good. 
• If tanks are placed in direct sunlight, the water temperature can fluctuate and cause the fish stress.
• Direct sunlight is the biggest cause of algae growth in the tank.
• Tanks near heaters or air conditioners can also cause temperature fluctuations that harm the fish.
• Tanks placed on uneven surfaces can cause leaks or cracks in the tank.

Living things

• You must be accountable and think responsibly when purchasing living things. 
• Fish differ in their final, adult size. Most fish sold in the fish store are young. Before purchasing, you need to find out how big that breed of fish grows. 
• Fish behavior are all different: Some are aggressive, territorial, nocturnal, diurnal, etc
• Most important is eating behavior. If the eating pace is very different, some fish can starve to death.
• Necessary fish tank size can differ based on the adult fish size and temperment. It is wise to do your research before. 

Lighting

• If your fish tank has plants, lighting is needed. However, without plants, lighting is not necessary. 
• Lighting can create a positive environment effect and thus be beneficial emotionally and psychologically. 
• It is good to use a timer to turn on lighting at regular intervals.

Water plants

• There are various water plants and each plant needs different lighting, nutrition and substrate.
• Water plants survive by eating various nutrients in the water.
• It is good to use a timer to turn on lighting at regular intervals.
• Most plants grow well when you put carbon dioxide into the tank.

Substrate

• Substrate is very important for water plants. You can purchase one especially made for water plants.
• There are some beneficial bacteria living in the substrate so it has a little filtering ability.
• Certain plants can live without substrates because they are easy to care for. 
• It comes in different colors so fish keepers can choose based on their preference.

Food feeding

• If you feed too much, the leftover food can rot and make the water go bad.
• If you feed too little, the weaker fish or the slow eating fish can starve to death.
• When choosing different breeds of fish for a single tank, you must take into consideration their eating temperament.
• Each breed of fish have different feeding characteristics, such as carnivore, herbivore, omnivore, etc. You need to choose fish food that fits their lifestyle.
• Giving worms or other live feed can deteriorate the water conditions faster. 

pH concentration

• Each fish breed has its own optimal pH level.
• Straying from the optimal pH can affect the lifespan of the fish and directly affect the health of the fish.
• Each district’s tap water has a different pH so it can be beneficial to pick a breed that can be kept in that specific pH.
• You can purchase pH adjusters but it needs to be used with caution.
• Fluctuation in pH can be detrimental to fish.