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12 Aquarium Tips for Beginners

Kate is a veteran aquarist who hopes her experience might help others avoid common mistakes.

Haider Kadhum

Haider Kadhum

Aquarium Tips and Tricks: A Beginner's Guide

An aquarium full of fish is a beautiful and captivating sight. People have enjoyed the wonder of aquariums for ages. Unfortunately, we don’t always understand all that goes into keeping happy and healthy fish before we get started. There is much to consider before you begin.

As a responsible pet owner, you must ensure you can properly care for any creature before you bring it into your home. It is not as simple as providing food and water. Following this guide will help you to avoid the most common mistakes.

12 Tips for Beginner Aquarists

  1. Choose an appropriately sized tank.
  2. Find a place for your aquarium.
  3. Know your fish.
  4. Condition your water.
  5. Cycle your tank.
  6. Perform regular water changes.
  7. Don't overstock your tank.
  8. Do not overfeed your fish.
  9. Use caution with new fish.
  10. Use caution with treatments and chemicals.
  11. Don't trust the salesperson.
  12. Join some aquarium groups.

Before we begin, I would like to warn you that this hobby can be quite costly. Caring for fish properly requires a filter, heater, and thermometer. To be able to appreciate the beauty of the tank, you will want a light, especially if you wish to have live plants. You will also need water testing kits to check the water chemistry, or you can bring a sample of your water to your local fish store and ask them to test it for you. Many places will test it for free.

You should have gravel or sand on the bottom of the tank, and you should also include plants and a shelter for fish to hide in when they are feeling stressed. To clean the tank, you will want a siphon to suck up debris on the bottom of the tank and to make water changes easier.

If you are on a tight budget, check on the internet for used tanks and equipment in your area. Before you purchase a used tank, ask the seller to fill it in front of you to ensure there are no cracks. Also take into account the increase in your electric bill. If I haven’t scared you off yet, let’s continue.

Emily Woolstenhulme

Emily Woolstenhulme

1. Aquarium Size

The first thing to consider is the size of the aquarium you wish to purchase. Most beginners start with a very small tank of only one or two gallons, thinking this will be easier to take care of. In fact, larger aquariums are much better for a new aquarist. It is highly recommended to start with at least 20 gallons for your first tank. Not everyone has the space or the budget for a tank of this size, of course, but try to start with the largest tank you can.

With a larger tank, it is much easier to keep the water chemistry and temperature stable. It is also usually recommended to get a tank that is longer than it is tall so your fish can have more room to swim back and forth. Make sure that your filter and heater are made for your tank’s size.

2. Aquarium Location

It is very important that you find the proper location for your fish tank. You will need a place that is away from any windows (Sunlight causes algae blooms). It should also be kept away from heaters or air vents. Choosing a low-traffic area will also be beneficial as it will be less likely to be accidentally bumped or disturbed.

Make sure your tank is level and has a sturdy stand that can support it. If it is tilted in one corner, it will cause stress on that part of the tank, which could lead to cracks and leaks. You will also want to make sure you have enough outlets nearby for all the equipment you will need.

3. Know Your Fish

Think very carefully about what type of fish you wish to keep. Aquarium fish have many different requirements depending on their place of origin. Even though you may see many species labeled “tropical,” that does not mean they all have the same needs. You will need to discover the preferred diet and water temperature as well as the desired water chemistry.

It is a good idea to keep fish together that come from the same region as they are more likely to have the same requirements. Also, consider how big each fish is supposed to get, and do not choose any species that could grow too large for your tank. Research their behavior to avoid placing predatory fish in your tank that will eat the other inhabitants that you have worked so hard to care for.

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Try to find species that occupy different areas of the tank. Some prefer to be near the top, while others hang out on the bottom. It is always a good idea to have a few “clean up crew” species to assist you in keeping the tank clean. These species feed on algae and leftover food that falls to the bottom.

4. Condition Your Water

Once you have picked out your tank, location, and the type of fish you wish to keep, you will most likely be chomping at the bit to get fish in your tank as quickly as possible. Try to be patient and remember that your water needs to be just right for the health of your fish. The first step is to add a water conditioner, which will de-chlorinate your tap water. Chlorine is very dangerous for fish and can cause necrosis (cell death) in their gills, leading to suffocation. Never add unconditioned water to your aquarium.

Rob Defreese

Rob Defreese

5. Cycle Your Tank

This is the most important step and is often skipped by those new to aquarium keeping. Fish waste releases ammonia into the water, which is harmful to fish. Special types of bacteria need to form in the filter to help with this problem. One type of bacteria converts ammonia into nitrite, which is even more toxic than ammonia. But another type of bacteria then converts the nitrites into nitrates which are not harmful at low levels. These bacteria need time to build up in your filter, and this process is called cycling.

There are two types of cycling—a fish cycle or a fish-less cycle. Ammonia is needed to start the process and can be added directly into the aquarium during a fish-less cycle, or it can be produced by adding a very small amount of fish (~1.5 fish per 10 gallons). While it may seem more exciting to choose the fish cycle, you have to keep in mind that the fish will be under some stress at the beginning as ammonia levels rise and the bacteria levels are low. It is considered more humane to choose the fish-less cycle. You can add 2-4ppm of ammonia with small amounts added every few days.

If you decide to cycle with a few fish, be very careful not to overfeed them as this will increase ammonia levels considerably. Be sure to do small water changes every few days (10–15%) to help reduce the stress of your fish. Cycling can take a long time, and it may not be complete for 8 weeks or longer. After 2–3 weeks, the water should be tested for ammonia and nitrite. Nitrite should spike around this time and will begin to be converted to nitrates.

When you have noticed this spike and then a subsequent drop in nitrite levels, you are able to add more fish. Add them slowly, only a few at a time. If you add them too quickly, you will start a cycle over again as the ammonia levels will rise. Adding plants will help keep nitrates down in your tank, and the plants should not be affected by rising ammonia levels. Remember that nitrates can be harmful in large amounts as well, so be sure to test your aquarium water regularly for ammonia, nitrites, and nitrates.

If you are feeling impatient and want to add fish right away but are concerned about the stress this will cause them, you can try products like Tetra’s SafeStart Plus that are supposed to add the live bacteria directly into your aquarium, but there have been mixed reviews on these products.

Nitrification Explained

6. Perform Regular Water Changes

There are many different opinions on how frequently you should change your water and how much to change. It largely depends on how stocked your tank is for its size. Changing 10–15% each week is the most recommended, 20% for tanks that are at maximum capacity. Lightly stocked tanks are able to go longer between water changes (~2 weeks). You should use a siphon to perform the water change to vacuum debris from the bottom of the tank.

Also remember that the beneficial bacteria live in the gravel or sand as well as the filter. Try not to clean both at the same time, or you will lose much of your bacteria and could start a cycle all over again. When you do clean your filter pads or sponges, be sure to clean them with tank water rather than tap water to avoid killing the bacteria. Do not use soaps or other cleaning products in your aquarium.

David Wilbur

David Wilbur

7. Do Not Overstock Your Tank

It is very important that you do not overcrowd your tank. An overstocked tank leads to stress and disease. A general guideline is 1 inch of fish per gallon. However, you should not place a fish that is meant to grow 10 inches in a 10-gallon tank. A common belief about fish is that fish growth is regulated by tank size.

While it may appear that way to a beginner, these fish will never be able to achieve their natural lifespan and often show deformities of the spine or skull. These fish have higher stress levels and are more susceptible to disease. Please only choose species that will thrive in the tank you have chosen.


One of the most abused species of aquarium fish is the goldfish. They have a very inefficient digestive system (they have no stomach, so food passes quickly) and produce a lot of waste. They also can grow quite large and are a social species that should be kept in groups. This means they should not be kept in a bowl and ideally should be kept in at least a 40-gallon or larger tank or pond. As a result, goldfish are not an ideal fish for beginners.

Betta or Siamese Fighting Fish

Another commonly abused fish is the betta or Siamese fighting fish. While it is true that they can sometimes inhabit small puddles temporarily in the wild, this is the toughest time of their life, and many bettas die in these small puddles during the dry season. They will try to jump to larger bodies of water, and most of their life, they thrive in rice paddies, marshlands, floodplains, ponds, river basins, and canals that stretch for long distances. They like areas that have little or no current and are thick with vegetation, but there is much more space than the common betta bowls you see in pet stores.

They can certainly survive in these little bowls thanks to their labyrinth (a breathing organ that allows them to breathe air at the surface), but they will not thrive in these conditions. A betta would be happiest in at least 5 gallons. They prefer water that is between 74–80 degrees Fahrenheit, so the tank should be large enough to accommodate a heater.

8. Do Not Overfeed Your Fish

While you are getting to know your fish, feed small quantities and watch to make sure your fish is eating everything before adding any more. Only feed what your fish will eat right away. You do not want extra food floating around in the tank. Feeding your fish twice a day is usually enough, but of course, research your fish species and make sure you know what they need.

Keep in mind that fish do best when they have a varied diet, just as people do. Freeze-dried foods can cause bloating and should be used as a treat on occasion rather than a daily meal.

Cassandra Caroline Starzl

Cassandra Caroline Starzl

9. Use Caution With New Fish

It is a good idea to have a quarantine tank available when you intend to buy new fish. This is especially true for saltwater fish from the ocean but is beneficial for freshwater fish as well. If you know your fish source is reliable you may be able to skip this step but it is always better to be safe than sorry. One sick fish can kill a whole tank very quickly. Select your fish carefully and do not choose one with damaged fins or gills.

If you notice any dead fish in the tank, it is better to wait and either check back another day or find another fish store. When you have picked out the fish you want, float the bag in your quarantine tank for at least 15 minutes to allow the water in the bag to gradually match the temperature of the water in the tank.

The quarantine tank can be quite simple. You can keep the decorations to a minimum but should provide hiding places for the new fish so it can feel safe. A bare bottom is fine and is easier to keep clean.

A good idea I have seen is to have an extra filter going in the main tank and then move it to the quarantine tank while in use so the filter will have the required bacteria to keep the water at healthy levels. You can use water from the main tank to fill this tank as well. You should keep your fish in this tank for 2–4 weeks. Some aquarium owners use this time to treat for parasites, but you should only use bacterial or fungal infection treatments if symptoms are present.

This tank can also be used as a hospital tank when you notice one of your fish showing signs of illness. This way you can isolate and treat them, reducing the risk of spreading the infection to the rest of the tank and protecting the other fish from exposure to unnecessary chemicals.

Do not use a filter with carbon in it as this kind of filter will remove any medication from the water. It is also a good idea to use a separate siphon and net for this tank to avoid contamination. Remember to perform frequent water changes while medicating as most medications will kill off the beneficial bacteria in the filter.

Beginner Species: I Do Not Recommend the Common Pleco—They Can Get Quite Large

10. Use Caution With Treatments and Chemicals

Do not add any chemicals or treatments to your tank until you completely understand their effects, both immediate and long term.

11. Don't Trust the Salesperson

While you can meet the occasional honest salesperson in pet stores, that isn't common. Most want to sell fish and equipment, and they will exaggerate or even lie if it means you will buy something. Research as much as possible and learn the signs of illness in fish so you can spot them right away. Also research filters and all other equipment carefully so you will not have to rely on the advice of a salesperson. Read reviews or ask a forum or social media group devoted to aquariums.

12. Join Some Aquarium Groups

I have learned so much from reading posts on the numerous Facebook groups devoted to aquarium keeping. These are great places for beginners to ask questions and get quick responses. Look for large groups with several thousand members for the fastest response time and the largest amount of experience to draw from.

Some that I have personally joined are Fish Tank Talk, Freshwater Aquariums, Aquarium Addicts, and Fish and Aquarium Discussion Group! In fact, the photos you see here have all been submitted by members of Fish Tank Talk. Thanks, guys!

Sven Stuttengaard

Sven Stuttengaard

Closing Thoughts

Please remember that an aquarium is not a decoration. It is a mini-ecosystem that is fully dependent on you. It is a big responsibility that should not be taken lightly. Some fish species live for many years, and you should be prepared to care for them their whole life before you decide to bring them into your home.

But in spite of the expense and work required, you may find that this hobby can become addictive, and before you know it, you will want one in every room. Many people do not realize how interesting and unique fish can be. Many are full of personality, and you can easily form attachments to them if you spend time watching them every day. If cared for properly, an aquarium is a magnificent sight and a fascinating piece of nature that you can enjoy for years to come.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2017 Nova Scott

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