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Beginners’ Guide: 5 steps to setting up a freshwater fish tank

Below you will find five simple steps that every beginner should know.  We’ve tried to make them simple but thorough enough for any situation though there are endless number of mistakes a beginner can make, and this guide can’t cover them all, we feel it will, when followed, increase the chances of a job well done and happy fish.

Step 1: Planning

Planning your new fish tank is the single most important step.  Failure to plan properly puts all the other steps in jeopardy. To start you must know the answers to a few basic questions.

  1. Where am I going to put it? Decide right off how much room you have for a tank and just where you are going to place it in your home or apartment. There are some important factors in regards to placement.
    1. Your tank is going to weigh a lot.
      • Water weighs about 8 pounds per gallon.
      • You will use about a pound of gravel per gallon.
      • This means your typical little 10 gallon tank will weigh about 100 pounds by the time you get water, gravel, decorations, heater, filter, etc. all hooked up.
      • Your apartment, second story bedroom, or home with a basement or raised floor, just might not be able to support the weight of a 500 pound 55 gallon tank. Know what your home can support.
    2. Temperature matters. Don’t place the tank too near a window.  This will generate too much heat, and also promote algae growth. Don’t place it too near a vent.  The heating or cooling will alter the environment of the tank. Fish need their water to remain the same as much as possible, not too hot, not too cool. Remember that goldfish are not tropical fish, they need their water cooler than the 76-78 degrees of a tropical tank.
    3. Don’t put the tank where it will get bumped frequently.  Even the slightest nudge, you will find, is like an earthquake to your fish and sends them into a stressed frenzy.
  2. How much money do I have to spend? With fishkeeping there is an up-front cost and there are recurring fees for food, filter media, light bulbs, and other various replacements.  If you think money will be an issue, pick a smaller tank with less fish.
  3. What kind of freshwater tank do I want? For each there are different needs.
    • Cold water tanks don’t require the expense of a heater but they are also limited as to what kinds of fish can be kept in them. While this is the most affordable option, it probably isn’t the best choice for a beginner. The lack of heat in the tank alters the biological processes of the tank and can make more frequent water changes a must.
    • Tropical tanks are very popular and only require the addition of a heater.  They can support a greater variety of fish, shrimp, and snails.  Beneficial bacteria will thrive in the warm waters and help breakdown waste more readily. This is the type of tank we recommend for a beginner.
    • Brackish water tanks have a high level of salt.  Not quite as much as a marine tank, but way more than a true freshwater tank. Bumble bee goby and green spotted puffers are two very popular brackish water species. This tank requires a heater and the added expense and effort of the high salt.  Because of this, we do not recommend this tank for a beginner.
  4. For the type of tank I have chosen what kinds of fish can go in it? Do your research. The Complete Book of the Freshwater Aquarium is a great resource.  It has plenty of the most commonly found species, their care, level of difficulty and size.  You don’t want to have a fish that will out grow the tank, so size is an important factor. Learn about all the fish and keep a list of the ones you want and why. Remember, it’s cruel to buy a fish and place it in the wrong environment only to have it die a sad and miserable death. This can all be avoided with just a little research.
  5. Which of those fish can live together? Not all fish get along.  Black red-tailed sharks, for example, tend to be aggressive toward like species.  Barbs are the same way.  A tin foil barb will attack a tiger barb.  These attacks can lead to serious fish injury and death. Just the stress of continued harassment can be enough to cause a fish to succumb to disease and waste away. Just because you like a fish, doesn’t mean you should buy it.
  6. Which of those fish are the easiest to care for? Once you have decided on the fish you like, and of those fish which can live as tankmates, then you must decide which of those fish you are most likely to keep alive.  Some fish are difficult and require pristine water conditions, something the beginner isn’t likely to achieve at first. Some fish have specialized diets that make feeding them difficult and expensive.
    • We recommend the following as hardy fish good for the beginner.
      • Peppered cory catfish (should have at least 3 for them to be happy).  They are good bottom dwellers that stay out of the way of other fish and keep the bottom clean.
      • Black Skirt tetras (should have at least 5 of them to be happy).  This schooling fish is easy to keep and is also quite affordable.
      • serpae tetras. Very similar to the black skirt tetra in body shape and care.  The main difference is their nice red color.
      • Betta (can actually live with the peppered corys).  This fish is generally solitary and requires a small tank.  Please, don’t keep them in a cup or tiny bowl.  While this is how you find them in the store, they do best in a tank of at least 1.5 gallons and even better in larger tanks.  They require very low water movement, can go a day or two missing a feeding, and breath air so don’t require as pristine water conditions as some other fish.
      • Sail-fin molly.  A larger, quick fish, that is very impressive to watch and tends to be quite hardy.
    • We advise against the following fish even though they are often sold to beginners.
      • Guppies. Require water to be well taken care of.  Will fight for dominance. If you have males and females they will breed.  While this may at first seem to be a wonderful thing, they will continue to breed, and you will soon have 30 fish that you have no room for and no idea what to do with.
      • Balloon belly mollies. Unlike the sail-fin molly, this mutation is not a particularly hardy fish and tends to die if water isn’t quite right.
      • Neon tetras.  People love these schooling fish, and with good reason, the bright colors flashing as they swim back and forth as a group is stunning.  Neons, however, do require good water conditions and are prone to disease of the water is less than pristine.  A great fish once you have at least six months under your belt.  They are worth the wait, but we do advise you wait.
      • Sharks.  These aren’t really sharks, but that’s the name this group of freshwater fish has been given due to the fact they look somewhat like their larger marine cousins.  The problem with sharks is their aggressive behavior.

Step 2: Buy the equipment

At this point you know how much money you have, how much space exists to place the tank, and what fish are to go into it.  By the largest tank you can afford and house. If you don’t, then it is very likely you will soon purchase a second tank spending more money than you wanted to.

  1. What kind of tank should you get depends partly on personal preference. Black or oak trim, depends on your likes and dislikes. Sometimes though, even if we like something, it doesn’t mean it’s the best purchase.
    • Black or clear silicone? Black is stronger.  However, this still remains largely aesthetic and most modern silicons are strong.
    • Tanks come in glass or acrylic.  Acrylic is lighter and reflects less, but scratches easily. For a beginner, we recommend glass because of it’s simply easier to care for and more forgiving.
    • The shape of your tank matters.  The good old fashioned rectangle is still the best bet.  It fits more places, is easier to decorate and maintain. If you have a smaller space, but would like the benefits of more gallons, then a bow front tank will work well. Also, remember, a deeper tank is more difficult to clean.  Don’t get one so deep you can’t reach the bottom when it is on the stand. You’ll be glad you thought about this later.
  2. What kind of filter should you get? In part this depends on how much money you have to spend.  If you have the money, we certainly recommend a 205 Fluval Aquarium Canister Filter – up to 40 Gallon or one of their larger filters. If you don’t have the extra money, for a considerable amount less we recommend the Tetra Whisper Power Filter.
  3. Your heater is important. There are heaters you can adjust and those that have a built in thermostat. Generally speaking, as far as the beginner is concerned, one that maintains the temperature itself is best because it requires no thought on your part. We recommend the Tetra Submersible 50-Watt Heater or one of the appropriate size for your tank.
  4. Do I need bubbles? The bubbles themselves do nothing inside the tank.  Their function is to agitate the surface of the water.  This promotes gas exchange. Co2 is released into the air and oxygen is taken into the tank. If your filter provides enough surface agitation, you won’t need an air pump.
  5. Do I need a power head? For larger tanks, like a 55 gallon tank, the answer is probably yes.  However, this will depend on the type of fish.  A Betta, and other such long finned fish, do not benefit from high circulation.  In fact, it can exhaust them to death.  Know the needs of your fish and that will help decide this.
  6. What about lighting? In most cases your tank will come with a hood and light.  If not, you will need these.  For your typical beginner tank (which we are to assume is not planted) a standard florescent light will do, nothing fancy is required.  A hood that covers the entire top of your tank will also help maintain temperature and reduce evaporation.
  7. How should I decorate my tank? While it would seem this is largely a matter of personal taste, it actually isn’t.  Your fish will require certain things in the tank to keep them happy.  Corys, for example, tend to like brown gravel.  A bright pink, while in keeping with our personal tastes, will cause them stress. Some fish are highly territorial and require clear divisions in the tank to make them feel at home, while other fish like places to hide.  All of these things must be kept in mind.  That said, there are a million different combinations of design you can use to accomplish the same thing. Enjoy the process.  While one person may not like a treasure chest that opens and closes, you may.  However, for the serious hobbyist, natural microcosms rule.
  8. A net or better yet a plastic hang on container.
  9. An algae scrubber.  Be sure if you have gotten an acrylic tank to buy one for use on that material.
  10. Set the equipment up. Follow the instructions that came with the equipment and put it all together.

Step 3: Let the tank mature

One day at a local PetSmart a woman was seen buying a large number of fish.  It seemed clear she had at least a 75 gallon tank judging by the numbers.  The PetSmart worker dutifully bagged up all of her new pets and helped her carry them to the checkout stand where she met her son.  While she got all the fish, her son, it turned out, had been purchasing the tank, filter, and other needful things. It was clear the intention was to take it all home, set it up, and drop the fish in.  What disaster this would certainly prove to be!

There’s a biological process that takes place inside your tank called the “nitrogen cycle” that must occur before it is ready to house fish.  As illustrated by the above story, many beginners simply don’t even know about this. The term “cycle” or “Cycling” is one you will hear repeated often in the hobby. This is because the understanding of this process is essential to your success. To read more about it see this article.

Once the tank has cycled, usually 2-6 weeks, it’s ready to accept fish and keep them healthy.

Nitrogen Cycle

Step 4: Buy the fish and food

At this point you should already know which fish you want and done all the research about their care and behavior. You know about how many your tank can hold (using their full grown size, not their small size at purchase). The general rule is 1 fish inch per gallons of water. There are certainly exceptions to this of which you will learn as time goes by, but as a beginner, this is a good rule to follow. There are a few things you should look out for when selecting the particular fish that will become yours.

  1. You are NOT at Walmart. Buying fish at Walmart will only encourage them to keep selling fish.  While it is possible that there exists a Walmart that takes good enough care of its livestock for you to consider making your purchase there, we have yet to find that Walmart.  In the aquarium hobby, Walmart’s reputation proceeds it. This isn’t to say you can’t get healthy fish there, if you show up on the right day. Based on our own experience, we simply cannot recommend it, especially for a beginner.
  2. The fish is behaving as it should. You’ve researched your fish, you know they should be lively, schooling, or sitting on the bottom.  If the fish in the store isn’t, then pick another specimen.
  3. Does it have an injury. Sometimes fish will fight, especially in the oft times overcrowded conditions of a pet store tank. Look over the fish to make sure all their fins are intact and that they don’t have any wounds.
  4. Does it have a disease. There are several fish diseases, all generally a result of poor water quality. If the fish seems bloated, and its scales are sticking out, that fish probably has dropsy and you shouldn’t buy it.  If the fish has small white spots all over it, the fish probably has ich and you shouldn’t buy it.  Ich especially can be contagious and so it is possible the entire tank is infected, even if you don’t see the signs on any of the other fish. It’s OK to go somewhere else, it’s a business and they won’t take it personally.
  5. Does it have good color. This is a tough one, and may require you getting familiar with your local fish shop.  All fish change colors when they are stressed, they become faded.  In most local fish shops’ the fish will be at some level of stress (AquaTouch is an exception to this). However, of the fish seems very pale, best to shy away from that one.
  6. Does the fish play well with others. As with all animals, temperament varies between individuals. Some fish are just timid and others just mean.  Spend several minutes watching the fish and if you notice one getting picked on or one that seems to be aggressive, don’t pick those fish.
  7. Not all fish stores will catch the exact fish you want, but most will give it a good try.  If they can’t try not to be too picky about it.  For one thing, the more they chase the fish, the more stressed it becomes so a quick capture is better. Also, capture into a container is better than into a net.
  8. Which brand of fish food. There are several good brands, but two we especially recommend.  For those on a budget Tetra makes a good quality and affordable product for every type of fish.  We’ve experienced very good results.  For those with more money to spend, Hikari brand is by far the best.  While tetra is a good brand, Hikari is vastly superior in quality. We especially recommend Hikari Bio-Pure FD Blood Worms.  These are a great treat for any fish and the main diet for some.

Step 5: Acclimate the fish and introduce them to the tank

Once you get the fish home, don’t drop them in the tank right away.  Place the unopened bag into the tank and let it float for about 15-20 minutes.  This allows the water in the bag to slowly become the same temperature as the water in the tank. A drastic change in water temperature can be very stressful on a fish. Place the fish in the tank.  Turn off the light. The next day turn the light back on and feed the fish.  All should be well.

As a quick side note there is some debate about the water the fish come in.  Many aquarists will never put that water in their tank. Depending on where you got the fish, this is true.  However, if you know the store well  then you may be comfortable just dumping the entire bag in.  If you didn’t get it at a place you are very familiar with you can pour the contents of the bag (fish and all) into a small container and then net the fish out for placement in the main tank. That said – better safe than sorry is a good rule of thumb and that means don’t put any of their water in your tank.


After you get it all set up and cycled and acclimated then you take care of it. That’s the part where you feed your fish, scrape the algae and change the water. What you feed your fish depends on what fish you have of course. That determines type of food and how often. For some fish you will feed them every day, twice a day, or even every other day. Fish like a betta eat only a small amount of food at a time. Fish like barbs eat quite a bit of food. Too much food can make the fish ill and foul your water. So research your fish. Less fish in a tank really is better so resist the temptation to buy everything you think is beautiful. Water changes should be done frequently. Daily, weekly, whatever, even monthly, depending on the bio-load of your tank.

Setting up your tank correctly to begin with gives you the best chance for success. So many new fishkeepers quit after a short time angry that their fish died and unaware that it was their fault because they rushed things. You can’t go buy a tank and bags full of fish then go home and toss it all together. That’s a recipe for disaster and upside down floating dead fish.

This is why fishkeeping is a hobby and like all hobbies there are rules, and processes to be followed. People who fly RC airplanes go through a process of flying beginner planes on easy-mode, then gradually get faster and more costly planes. Eventually they may even construct their own and participate in competitions. All along the way they are patient with the building and the flying. The hobby of fishkeeping is no different. Practice, patience, and study, lead to success. And success in fishkeeping means not just fish that are alive, but fish that thrive, grow well, and perhaps even breed in your tanks. Let me know how it goes!