"Aquarium fish make us realize how beautiful silence is." - Unknown

Caring for your fish and aquarium maintenance requires daily observation - and it's easy to keep healthy fish and a super clean tank. Fish are interesting and entertaining. Fishkeeping practiced by aquarists is a fun and rewarding activity that can provide years of enjoyment, education, and stress relief. Many people believe that fish care is easier than taking care of any other kind of pet, and there are so many different kinds of fish you can keep in a tank. Betta fish (Siamese fighting fish) have vibrant colors and are fascinating to watch. They can be easier to take care of than many other types of fish - so they may be good for beginner aquarists. The best thing about all pet fish is they are quiet!

Choose fish with care - most large fish will view smaller tankmates as potential prey, even if both are sold as community fish.  For example, angelfish will catch and eat neon tetras given the chance.

Fish Care Benefits

  • Fish don't need to go for walks, require shots, shed, need vet care, or eat a lot.
  • Fish do not have bad breath or drool on you - no matter how happy they are to see you!
  • Fish do not like to be petted like a dog.
  • Dogs and cats can bite - but fish do not.
  • Dogs and cats pee and poo, fish just poo.
  • Fish never get bored and don't have separation anxiety.
  • Fish will never run away, chase cars, or dig up a yard. Have you ever seen a LOST FISH sign?

Not only are fish low-maintenance and inexpensive, their bright colors and tranquil environment can brighten up any home, making them an ideal pet choice for people who love animals, but have less space, and less time.

They are also perfect pets for people with allergies to dogs or cats, or for small children learning to care responsibly for an animal for the first time.

When choosing fish for your aquarium tank there's a lot to consider, because there are more than 25,000 identified species of fish, and about 2,000 of them from goldfish to exotic tropical fish that can thrive in a home aquarium. It is estimated that there may be over 15,000 fish species that have not yet been identified.

There are more species of fish than all the species of amphibians, reptiles, birds, and mammals combined. 40% of all fish species inhabit fresh water, yet less than .01% of the earth's water is fresh water.

Fish have been on the earth for more than 450 million years and were well established long before dinosaurs roamed the earth. They live in nearly every large body of water in the world including streams, rivers, ponds, lakes, and oceans. Fish have gills for "breathing" oxygen in water, and fins for propelling and steering their body through water.

Fish Tank Details

The best place for an aquarium tank is a hard, flat surface. Small tanks of 30 gallons or less can be placed on a sturdy countertop or table but larger tanks require a proper cabinet or supporting structure. Make sure the ground is flat because uneven pressure against the walls of the aquarium can cause damage over time.  If you have cats, make sure the lid covers the tank and can't be pushed off. The lid also needs to be firm enough if your cat jumps onto it, it will not break, slip, or fall into the tank itself.

Choose a spot close to an electrical outlet because you will need to power the light, filter, and heater. Avoid extension cords if possible to keep the wires at a minimum.

You can keep 1 inch of fish per gallon. But, fish are very susceptible to stress from temperature changes and water conditions, so a 5-gallon tank will change temperatures and water conditions faster and pollute more easily than a larger tank. Strangely enough, a bigger aquarium requires less maintenance. Small aquariums are much harder to keep the water balance correct, are easy to overcrowd, and rotting food or vegetation can have an immediate bad effect on the health of the fish.

Always understock a tank rather than overstock!

In the wild, fish live in large bodies of water that they can move around in to stay in the same temperature and water conditions. They are not very tolerant of the wide swings in temperature and water conditions a small tank will expose them to.

Aquarium Shapes
Decide on a tall or wide aquarium. Fish generally live either on the bottom, at the top, on in the middle of the aquarium. Your fish won't be crowded if you have 1/3 of each type, but keeping all bottom fish in a tall tank is bad. A long aquarium allows fish at each level to spread out but compresses them together vertically. Some fish are very territorial and spreading them out is a good idea. It depends on the kind of fish you buy - match your tank to your fish, not to your decor.  Basically, a rectangular aquarium is still the best.  Other shapes, with a smaller surface area compared to water volume, will often need more frequent water changes and more maintenance.

Aquarium Shapes

Glass or Acrylic Aquariums

Both materials for aquariums have their advantages and disadvantages. The traditional glass aquarium is heavy and can spring leaks at the seams. Leaks are easy to fix however and usually only occur in an older aquarium. They are usually cheaper than acrylic aquariums. They only come in rectangular or square shapes.

The newer acrylic aquariums are lighter than glass and come in all kinds of shapes. They rarely spring leaks as there are no seams. They are more expensive than glass aquariums but generally last longer. They are easy to scratch however so never clean with any kind of abrasive chemical or other chemicals which can fog the glass. Acrylic aquariums used to yellow with age but the newer materials stay clear throughout their lifetime.

Freshwater or Saltwater Fish

If you are just starting out, go fresh. Water conditioning is more difficult with saltwater fish. However, all the really brightly colored fish are saltwater. Consequently, there are rewards for learning to manage a saltwater aquarium. In addition, you can create a very interesting "reef aquarium" with saltwater that includes sea urchins, coral, and other marine bottom dwellers.

Freshwater fish can be either cold-water or tropical species. Fish are fascinating pets and depend on you for their care and environmental health, so maintain a healthy place for them to live. Managing the water temperature, hardness, and pH level is probably the hardest thing about owning fish. Not all fish get along, and some large fish see smaller fish as prey. Before you buy your fish, research whether the combination of fish and the size of your tank is appropriate. Fish are sensitive to their environment - understanding the conditions they need to thrive is important for survival.

Fish Feeding Cycle

12 Problems Beginning Aquarists Experience

1. Starting With Too Small Aquarium

Small aquariums can be more difficult to maintain than larger tanks and are not well-suited to beginners. Conditions tend to be more stable in larger aquariums, and if things start to go wrong, you have more time to correct them. A first-time aquarist can start out with 20-55 gallons. Always start with the largest aquarium your space and budget allow.

2. Buying Fish and Putting in Tank Before Cycling Tank

A newly set up aquarium is not ready for fish on the first day. A new aquarium setup should be run for a minimum of 2-3 days before the first fish are introduced.

3. Not Cycling the Aquarium

It takes time to establish the biological balance in an aquarium. While there are products on the market that help speed up this process, the safest way to cycle a newly set up aquarium is to add just a few fish initially, feed sparingly, test ammonia and nitrite levels until they stabilize at zero before adding more fish. Repeat this process until the aquarium is fully stocked.

4. Not Testing the Water in a New Aquarium

It's impossible to know if ammonia or nitrite problems are developing, or it's safe to add fish to your new aquarium without testing the water. Existing fish often adjust to slowly rising ammonia and nitrite levels and may not show signs of distress until it is too late. New fish can be severely stressed if added to an aquarium with high levels because they do not have time to adjust. There is no magic "safe" time interval for adding new fish, and you can't see ammonia or nitrite in water. Testing is the only way to know if your aquarium water is safe.

5. Putting Too Many Fish in Your Aquarium Tank

When you are new to fishkeeping, you want to buy every fish you see. But there is a limit to how many fish a new aquarium can hold, regardless of how large it is or how efficient the filter is. Many fish grow larger after they are purchased, and some fish are territorial and become aggressive when crowded with other fish. Keep fewer fish in your aquarium rather than too many.

6. Feeding Too Much

It's normal to worry about your fish going hungry, but you can cause more harm by feeding too much. Fish fed once or twice a day is sufficient, and all food should be consumed within 2 minutes. Uneaten food can pollute the water and cause ammonia and nitrite levels to rise.

7. Buying the Wrong Size Filter

Most aquarium filters are rated according to how many gallons the aquarium holds. This rating system works well most of the time, but there is no "one-size-fits-all" best filter. There are many different sizes and flow rates. Consider the needs of your aquarium such as your stocking levels, water circulation, and ease of use. It is important to know what type of fish you plan on having before you purchase a filter. Fast-moving fish love filter flow and can handle powerful currents. Slow-moving fish can tire or die if exposed to constant filter flow and need more gentle filtration.

8. Impulse Buying

Always research new fish before purchasing them to make sure they are compatible with existing inhabitants and will not outgrow your aquarium. Some fish have special water chemistry needs such as lower pH or alkalinity, which your tap water may not provide. Also, if fish you are considering buying are specialized feeders, make sure you provide the proper food for them.

9. Leaving the Aquarium Light on All the Time

Like all animals, fish need a resting period, and it should be the same period every day. In nature, the day/night cycle is fairly consistent, especially in the tropics. Leaving the aquarium light on all the time stresses your fish and contributes to unsightly algae growth. Putting your aquarium light on a timer is an easy way to provide a consistent light cycle. If the aquarium is used as a night light in a child's bedroom, turn the light off and draw the curtains during the day to simulate nighttime for your fish.

10. Cleaning Too Much

When an aquarium is first set up, the biological balance is fragile and unstable. Avoid scrubbing ornaments, stirring or vacuuming the gravel, or cleaning the filter when it doesn't really need it, as this can destroy beneficial bacteria and upset the balance. If your aquarium or filter seems to need cleaning in the first 2 to 3 weeks after setup, the filter may be too small for the job, you may have too many fish, or you may be overfeeding.

11. Topping Off for Evaporation Instead of Doing a Water Change

Adding water to your aquarium when it evaporates is called "topping off". Doing this instead of performing a water change regularly will result in an accumulation of pollutants such as nitrate and phosphate and a drop in pH and alkalinity. This stresses your fish and leaves them more susceptible to disease. Change 10% of the water in your aquarium every week or 25% every 2 weeks.

12. Insufficient Cover

Aquarium decorations provide habitat, make your fish feel secure, reduce stress, and enhance their colors. Fish often hide because there are not enough decorations in the aquarium, seeking refuge behind a heater, filter tube, or other objects.

Fish Breeding

Some fish will spawn in aquariums while others are very difficult to coax into breeding in captivity.  Fish are either livebearers or egg layers.  After fertilization, it will typically take about 4 weeks before the fry is born. The fry is not born until it is developed enough to survive without any help from the parents.

Livebearing fish give birth to free-swimming fry and the offspring develops inside the female fish.

Egg layers will instead release eggs that are fertilized outside the female fish. Eventually, the eggs will hatch, and the fry will emerge.

If you are a beginning aquarist and want to try breeding fish, livebearers are usually a better choice than egg layers, since there are several livebearing species that will happily spawn in aquariums without any extra care or treatment. Molly, Guppy, and Platy are commonly kept livebearers.

Livebearers give birth to fry that look like tiny copies of adult fish. But the fry is protected by a duller and camouflaging color, and they lack extravagant features that are found in mature fish.

Fish FAQs

  • Most fish sleep with their eyes open because they have no eyelids, but some sharks do have eyelids.
  • There are more species of fish than all the species of amphibians, reptiles, birds, and mammals combined.
  • Some species of fish can fly (glide), others can skip along the surface, and some can even climb a rock.
  • An ichthyologist is a scientist who studies fish.
  • Fish are divided into 3 main groups: jawless fish, cartilaginous fish, and bony fish.
  • A seahorse is actually a fish.
  • The largest fish is the great whale shark which can reach 50 feet in length and weigh up to 15 tons.
  • Maturing at less than 1/2 inch in length, dwarf pygmy gobies (Pandaka pygmaea) are some of the smallest fish in the world.
  • The fastest fish is the sailfish - it can swim more than 60 miles an hour.
  • A walking catfish can live out of water for days at a time. They have a special chamber in their lungs to help them breathe.
  • There are over 25,000 identified species of fish on the earth.
  • Some deep-sea fishes attract prey with specialized light organs. (e.g. Anglerfish)
  • Some fish like sharks don't have an air bladder to help keep them afloat and must either swim continually or rest on the bottom.
  • Fish have a specialized sense organ called the lateral line, which works similar to radar and helps them navigate in dark or murky water, detect changes in water temperature, pressure, and current.


Fish are good pets! You always know where they are because they stay in a tank in the room. The vibrant colors, shapes, and sizes are interesting to watch, and over time you may find that they have their own personalities.

Taking care of fish can be good starter pets to teach children about the responsibilities of owning a pet. Lastly, watching your fish swim around the water in their aquarium has a calming, tranquil effect.