Aquarium Basics

Understanding the fundamental aspects of aquarium care is crucial for creating and maintaining a thriving aquatic environment. Key considerations include selecting an appropriate tank size, understanding the nitrogen cycle, and establishing a suitable habitat for aquatic life. Proper tank setup and maintenance, including water conditioning and regular water testing, are essential for ensuring a healthy and stable aquatic ecosystem.

1. What is an Aquarium?

An aquarium is a contained environment, typically a glass or acrylic tank, designed to house aquatic organisms such as fish, invertebrates, and plants. It provides a controlled habitat where the water quality, temperature, and lighting can be regulated to support the well-being of the inhabitants.

Aquariums are not only visually captivating but also serve as educational tools, allowing enthusiasts to observe and appreciate the diverse marine life within a confined space.

2. Understanding Aquarium Terms

Before you start creating your aquarium, it’s important to understand some basic aquarium terms. Here are some of the most common terms that you should know:


Cycling refers to the process of establishing a biological balance in your aquarium. This involves cultivating beneficial bacteria that convert harmful ammonia, produced from fish waste, into safer substances like nitrate. This process is essential before adding fish to your new aquarium.


pH is a measure of the acidity or alkalinity of your aquarium water. The pH scale ranges from 0 to 14, with 7 being neutral. A pH level of 7.0 is ideal for most freshwater fish. However, some fish species may require a slightly different pH level.

Nitrogen Cycle

The nitrogen cycle is a natural process that occurs in your aquarium. It involves the conversion of ammonia to nitrite and then to nitrate. Ammonia is produced by fish waste, uneaten food, and decaying plants. Nitrite is also toxic to fish, but it is less harmful than ammonia. Nitrate is the least harmful of the three nitrogen compounds and can be removed through regular water changes.


Filtration is the process of removing waste and debris from your aquarium water. There are three types of filtration: mechanical, chemical, and biological. Mechanical filtration removes physical debris from the water, chemical filtration removes impurities, and biological filtration removes harmful nitrogen compounds.

Water Change

A water change involves removing a portion of your aquarium water and replacing it with fresh water. This process helps to remove excess nutrients, waste, and harmful compounds from your aquarium water. Regular water changes are essential to maintaining a healthy aquarium environment.

3. What Do I Need For a Fish Tank?

There are a few basic things you need for your new aquarium to get started:

  • Tank: The first thing you need is a tank. The size of the tank depends on the number and size of fish you plan to keep. A larger tank is always better as it provides more swimming space and surface area for air exchange. A 20-gallon tank is a good starting point for beginners.
  • Filter: A filter is essential for keeping the water clean and healthy for your fish. It removes waste and debris from the water and helps maintain the water quality. Choose a filter that is appropriate for the size of your tank.
  • Heater: A heater is necessary to maintain a consistent water temperature for your fish. Most fish require a temperature between 72 and 82 degrees Fahrenheit.
  • Thermometer: A thermometer is needed to monitor the water temperature and ensure it stays within the appropriate range.
  • Substrate: Substrate is the material that lines the bottom of the tank. It provides a natural environment for your fish and helps maintain water quality. Gravel, sand, and crushed coral are popular choices for substrate.
  • Water conditioner: Tap water contains chemicals that can harm your fish. Water conditioner removes these harmful chemicals and makes the water safe for your fish.

Fish Tank Setup Checklist:

To ensure that your fish tank is properly set up and ready to become a thriving home for your fish, this checklist covers all the basic aquarium needs.

  • Aquarium
  • Aquarium filter
  • Aquarium lighting
  • Aquarium heater
  • Thermometer
  • Substrate
  • Fish food
  • Water conditioner
  • Fish net
  • Decorations or plants
  • Test kits for monitoring water parameters
  • Gravel cleaner

For an in-depth explanation of each component and its importance in your freshwater aquarium, check out the Freshwater Aquarium Setup Checklist.

4. Understanding the Aquarium Ecosystem

Aquariums are not just a container of water with fish swimming inside. They are complex ecosystems that require careful attention to maintain a healthy and thriving environment for aquatic life. Understanding the basics of the aquarium ecosystem is crucial for keeping your fish and other aquatic creatures healthy.

The Nitrogen Cycle

The nitrogen cycle is a crucial process in the aquarium ecosystem. It is the process by which toxic ammonia is converted into less harmful nitrate. This process is carried out by beneficial bacteria that live in the aquarium filter. The nitrogen cycle must be established before adding fish to the aquarium. It is important to monitor the levels of ammonia and nitrite in the water to ensure that the nitrogen cycle is working properly.

Water Chemistry Basics

Water chemistry is another important aspect of the aquarium ecosystem. The pH level of the water must be maintained within a specific range to ensure the health of the fish. The ideal pH range for most freshwater fish is between 6.5 and 7.5. It is important to test the water regularly to ensure that the pH level is within the desired range. In addition to pH, the hardness of the water should also be monitored.

Temperature Regulation

Temperature regulation is also crucial for the health of the aquarium ecosystem. The temperature of the water should be maintained within a specific range depending on the type of fish in the aquarium. Most tropical fish require a water temperature between 75 and 80 degrees Fahrenheit. It is important to monitor the temperature of the water regularly and make adjustments as needed to maintain the desired temperature.

5. Setting Up Your Aquarium

When it comes to setting up your aquarium, there are a few key factors to consider to ensure the health and happiness of your aquatic pets. Follow these simple steps to get started:

Choosing the Right Tank Size

The size of your tank will depend on the type and number of fish you plan to keep. As a general rule, a larger tank is better as it provides a more stable environment and allows for a greater variety of fish. A 20-gallon tank is a good starting point for beginners, but if you have the space and budget, a 50-gallon or larger tank is ideal.

Filtration Options

Proper filtration is essential for maintaining a healthy aquarium. There are several types of filtration systems available, including hang-on-back filters, canister filters, and sponge filters. Each type has its own pros and cons, so it’s important to do your research and choose the best option for your specific needs.

Lighting Requirements

Lighting is another important factor to consider when setting up your aquarium. Most fish require 8-12 hours of light per day, so it’s important to choose a lighting system that can provide this. LED lights are a popular choice as they are energy-efficient and provide a wide spectrum of light. Additionally, live plants require a specific type of light to thrive, so be sure to choose a lighting system that can accommodate them.

6. Water Quality Management

Maintaining good water quality is essential for the health and well-being of your aquarium inhabitants. Poor water quality can lead to stress, illness, and even death. Here are some key factors to consider when managing your aquarium’s water quality.

Why Water Quality Matters

Fish produce waste that can accumulate in the water and become harmful to them. Testing your aquarium water regularly for ammonia, nitrite, and nitrate levels is crucial. High levels of these compounds can cause stress and illness in fish. Additionally, minerals in the water can affect the pH, hardness, and alkalinity levels, which can also impact your fish’s health.

Cycling the Aquarium

Before adding fish to your aquarium, it’s important to cycle the tank. Cycling is the process of establishing beneficial bacteria that help break down fish waste. This process can take several weeks, but it’s crucial for maintaining good water quality. You can cycle your aquarium by adding fish food to the tank to simulate waste, or by using a bacterial supplement.

Water Testing Procedures

Testing your aquarium water regularly is essential for maintaining good water quality. You should test for ammonia, nitrite, nitrate, pH, and water hardness. You can use test strips or liquid test kits to measure these levels. Make sure to follow the instructions carefully and record your results.

Maintaining Water Parameters

Once you’ve established good water quality, it’s important to maintain it. Regular water changes are essential for removing excess waste and maintaining proper water parameters. You should aim to change 10-20% of the water in your aquarium every week. Additionally, make sure to clean your filter regularly to prevent the buildup of debris.

7. Aquarium Maintenance

Maintaining your aquarium is crucial to keeping your aquatic pets healthy and happy. Proper aquarium maintenance involves regular cleaning and water changes, as well as monitoring water quality and testing water parameters. Here are some tips to help you keep your aquarium in top condition.

Regular Cleaning Schedule

Cleaning your aquarium regularly is essential to keeping it healthy. You should clean the tank and all equipment every two weeks to remove debris and waste. This includes cleaning the gravel, wiping down the glass, and cleaning the filter. Be sure to use a siphon to remove any excess food or waste from the bottom of the tank.

Fish Health Checks

One of the most important aspects of aquarium maintenance is monitoring the health of your fish. You should observe your fish daily to ensure they are swimming and behaving normally. If you notice any changes in their behavior, such as lethargy or loss of appetite, it may be a sign of illness. In such cases, you should isolate the affected fish and treat them accordingly.

Water Change Techniques

Regular water changes are necessary to remove waste and maintain good water quality. You should aim to change 10-20% of the water in your aquarium every two weeks. To do this, you can use a siphon to remove the water and replace it with fresh, conditioned water. Be sure to match the temperature and pH of the new water to the existing water to avoid shocking your fish.

Testing Water Parameters

Testing your water regularly is essential to maintaining good water quality. You should test your water every two weeks to monitor the temperature, pH, and ammonia levels. You can use a test kit to do this, which will give you accurate readings of these parameters. If you notice any changes in the water quality, you should take action immediately to correct the problem.

8. Fish and Plant Selection

When selecting fish and plants for your aquarium, it is important to consider compatibility and balance. Here are some factors to keep in mind:

Choosing Compatible Fish Species

Choose fish species that are compatible with each other and with the size of your tank. Some fish may be aggressive towards others, while others may require a specific water temperature or pH level. Research the needs of each species before making a purchase.

Live Plants vs. Artificial Decorations

Live plants not only add beauty to your aquarium, but also provide oxygen and help maintain water quality. However, they may require more maintenance and care than artificial decorations. Artificial decorations are a low-maintenance option, but they do not provide the same benefits as live plants.

Creating a Balanced Habitat

A balanced habitat in your aquarium involves creating a natural ecosystem that supports the needs of both fish and plants. This includes maintaining proper water quality, providing adequate lighting and filtration, and ensuring a suitable substrate for plants to grow in. A balanced habitat will result in a healthier and more vibrant aquarium.

9. Feeding and Nutrition

When it comes to aquariums, feeding your fish is one of the most important aspects of their care. Proper nutrition is essential for their health and well-being. In this section, we will discuss the different types of fish food, feeding schedules, and nutritional requirements for different fish species.

Types of Fish Food

There are several types of fish food available on the market, including dry flakes, frozen foods, pellets, and even some fresh meat and vegetables. When selecting fish food, it’s crucial to consider the dietary needs of your fish species. Some fish are meat-eaters (carnivores), while others are vegetation eaters (herbivores). Therefore, it’s essential to choose the right type of food to meet their nutritional requirements.

Feeding Schedules

A general rule of thumb is to feed your fish only what they can consume in 2 to 3 minutes. Overfeeding fish can cause health problems, such as obesity, constipation, and poor water quality. Therefore, it’s crucial to establish a feeding schedule that works for your fish species. Some fish require multiple small feedings throughout the day, while others only need to be fed once or twice a day.

Nutritional Requirements for Different Fish Species

Most aquarium fish are omnivores and require a balanced diet that includes both meat and plants. However, some fish species have specific nutritional requirements that must be met to maintain their health and well-being. For example, plant-eating fish cannot properly digest animal-based foods, while strictly carnivorous fish cannot obtain the proper nutrients from a plant-only diet. Therefore, it’s essential to match the food to the dietary needs of your aquarium fish.

10. Health and Disease Prevention

Keeping your aquarium inhabitants healthy is crucial to their survival. Fish can be susceptible to a variety of diseases, but there are steps you can take to prevent them from occurring.

Common Fish Diseases

Some common fish diseases include ich, fin rot, and velvet. Ich is a parasitic disease that causes white spots on the fish’s body. Fin rot is a bacterial infection that causes the fins to deteriorate. Velvet is a parasitic disease that causes a yellowish-gold dusting on the fish’s body.

Quarantine Procedures

Quarantining new fish before introducing them to your aquarium is an effective way to prevent the spread of diseases. During the quarantine period, you can observe the fish for any signs of illness and treat them accordingly. It is recommended to quarantine new fish for at least two weeks.

Medication and Treatment Options

If you notice any signs of illness in your fish, it is important to act quickly. There are a variety of fish medications and treatment options available, including antibiotics, antifungal medications, and salt baths. It is important to follow the instructions carefully and only use medications that are safe for your fish.

In addition to these steps, maintaining good water quality and providing a healthy diet can also help prevent diseases in your aquarium.

11. Advanced Aquarium Topics

If you’ve mastered the basics of aquarium keeping and are ready to take your hobby to the next level, there are a variety of advanced topics you can explore. Here are a few areas to consider:

Breeding Fish

Breeding fish can be a rewarding and challenging experience. With the right setup and knowledge, you can breed a variety of species, from livebearers like guppies and mollies to egg-laying fish like cichlids and tetras. To get started, you’ll need to research the specific breeding requirements of your chosen species, provide the right conditions for spawning, and care for the fry once they hatch.

Custom Tank Building and DIY Projects

If you’re looking to create a truly unique aquarium, consider building your own custom tank or adding some DIY projects to your setup. You can build tanks in a variety of shapes and sizes, from traditional rectangles to hexagons, cylinders, and more. You can also create custom backgrounds, lighting systems, and other features to make your aquarium stand out.