Aquarium Terms

enturing into the world of aquariums can be as complex and diverse as the ecosystems they contain. With a multitude of terms to understand, from water chemistry to habitat setup, a clear glossary is an essential tool for both beginners and seasoned aquarists. Knowing these terms not only aids in the care and maintenance of your aquatic environment but also enhances your ability to navigate the hobby with confidence.

Acclimation, for example, is a critical process that involves slowly adjusting fish to the temperature, pH, and salinity of their new environment, vital for reducing stress and ensuring their health. As you become familiar with terms like ‘acidic’, referring to water with a pH below 7, or ‘acanthastrea’, a type of stony coral, you’ll find that communicating with fellow hobbyists and professionals becomes much easier.

Understanding specific terms can guide you in creating an ideal habitat for your aquatic life, such as knowing the importance of calcium carbonate for increasing water hardness or recognizing the nutritional value of brine shrimp as a food source. This base of knowledge is not merely academic; it directly impacts the well-being and flourishing of the fish and invertebrates in your care.

Types of Aquariums

Before setting up an aquarium, it’s important to understand the different environments you can recreate. Each type requires specific equipment and care to provide the best habitat for the aquatic life it houses.

Freshwater Aquariums

Freshwater aquariums are perhaps the most common type you’ll encounter. These setups mimic river, lake, or stream environments and are often easier to maintain due to the wider range of temperature and pH levels that the inhabitants can tolerate. They are an excellent choice for beginners and can house a variety of fish, plants, and decorations.

Saltwater Aquariums

Saltwater, or marine, aquariums replicate the ocean environment and require a precise balance of salinity, temperature, and pH. They often include brightly colored fish and can contain intricate rock formations. Properly maintaining a saltwater tank is typically more demanding than a freshwater setup, making it suitable for more experienced aquarists.

Reef Aquariums

Reef aquariums are a type of saltwater system, distinguished by their focus on supporting the growth of corals and other invertebrates. These tanks demand intense lighting, stable water conditions, and specific water chemistry to cater to the needs of the delicate reef-building organisms. It’s a challenging yet rewarding type of aquarium that showcases the complexity of marine ecosystems.

Brackish Aquariums

Brackish aquariums combine elements of freshwater and saltwater environments, simulating estuaries where rivers meet the sea. These tanks house unique species that require moderate salinity levels, typically achieved by mixing fresh water with reef salt. The specific gravity of the water needs to be carefully monitored to ensure the well-being of the brackish water species.

Aquarium Equipment

Selecting the right equipment is crucial for maintaining a healthy aquatic environment for your fish. Each piece of equipment has a specific role in creating optimal living conditions in your aquarium.


Filters are essential for keeping your tank water clean and clear. Mechanical filters remove particulate matter, biological filters facilitate beneficial bacterial growth to break down ammonia, and chemical filters, like activated carbon, remove impurities and taints from the water.


Proper lighting not only showcases your aquarium, but it also supports the health of plants and fish. Fluorescent and LED lights are commonly used for their efficiency and longevity. It’s important to provide a balanced light cycle to mimic natural conditions.


Heaters ensure that your aquarium maintains a consistent and suitable temperature, which is vital for tropical fish. You’ll typically choose a heater based on your tank’s size, aiming for approximately 2.5 to 5 watts per gallon.

Air Pumps

Air pumps are used to increase oxygenation and circulation in aquarium water. They drive air into the water through tubing and airstones, creating bubbles and water movement that supplement the filtration system.


The substrate forms the bed of your aquarium and can affect water chemistry, filtration, and the well-being of your tank’s inhabitants. Options include gravelsand, and specialized plant substrates designed to support aquatic plant growth.

Aquarium Maintenance

Maintaining an aquarium is integrally tied to ensuring the health of your aquatic pets and plants. Tasks such as regular water changes, testing water parameters, controlling algae, and proper aquascaping play a critical role in the thriving ecosystem of your fish tank.

Water Changes

You should perform water changes weekly to remove toxins and replenish essential minerals. Replacing 10-15% of the total volume is typically sufficient to maintain a balanced environment. Remember to use water that is the same temperature to avoid shocking your fish.

Testing Kits

Regular water testing is vital for detecting any changes in pH, ammonia, nitrite, and nitrate levels. You should test your water weekly with a reputable aquarium testing kit to catch any imbalances early, allowing you to address them before they threaten the tank’s inhabitants.

Algae Control

Controlling algae is imperative in keeping your tank clean and your fish healthy. Manual removal, limiting light exposure, and employing natural algae-eaters can all serve as effective strategies. Introduce algae-eating fish or invertebrates to bolster your defense against unwanted growths.

Aquascaping Tools

To create and maintain a visually appealing and functional environment, you’ll need the right tools, such as aquascaping scissors, tweezers, and substrate spatulas. Use these tools to trim plants, position decorations, and manipulate substrate, facilitating an aesthetically pleasing and healthy aquarium landscape.

Aquatic Life

In your aquatic ecosystem, the living inhabitants such as fish species, plant varieties, and invertebrates each play a crucial role. It’s important to understand their specific needs and roles to maintain a balanced and thriving aquarium.

Fish Species

Fish are the main characters of your aquarium, bringing movement and color to the underwater world. Each species has its own requirements for water parameters, space, and social dynamics. For instance, Bettas prefer solitary living and calm waters, while Neon Tetras thrive in schools and active environments. Always research the compatibility of fish species to ensure a harmonious community tank.

Plant Varieties

Aquatic plants not only provide aesthetic value, but they also enhance water quality and create a natural habitat for your fish. Java Fern and Anubias species attach to rocks and wood, requiring minimal substrate, whereas Amazon Swords and Cryptocorynes need nutrient-rich substrates to flourish. The right plant selection can greatly improve the ecological balance in your aquarium.


Invertebrates such as snails, shrimps, and corals add diversity to your tank and can be beneficial for algae control and cleaning. Shrimps like the Cherry or Amano are algae eaters and active throughout the day. Snails, including Nerite or Mystery snails, help by scavenging leftover food and detritus. Corals, although more demanding in terms of care with needs for strong lighting and stable water conditions, offer a stunning visual appeal and complexity to reef aquariums.

Aquarium Set-Up

Setting up your aquarium correctly is crucial for the health of your fish and plants. This includes understanding the cycling process, designing your aquascape, and choosing the right fish to stock your tank.

Cycling Process

Before introducing fish to your aquarium, you must establish a biological filtration system through the cycling process. This involves cultivating beneficial bacteria to convert toxic ammonia, produced by fish waste, into less harmful substances like nitrites and nitrates. Start by setting up your aquarium and filter, then add ammonia sources like fish food or pure ammonia, monitoring levels with test kits until they stabilize.


Aquascaping is the artful arrangement of rocks, plants, and substrates in your aquarium. It’s not only about aesthetics; the layout can affect fish behavior and tank health. Use inert materials to avoid altering water chemistry. When positioning plants, consider their light and space requirements to thrive, alongside creating hiding spots for your fish.


When it’s time to stock your aquarium, choose fish that are compatible in terms of size, temperament, and environmental needs. Start by adding a few fish and gradually increase to avoid overwhelming the filtration system. Remember to research each species’ needs—for example, schooling fish prefer groups, while others may require specific water conditions.

Fish Health

Maintaining fish health is a crucial aspect of managing an aquarium. A good understanding of common diseases, treatment options, and quarantine procedures is essential for the longevity and well-being of your aquatic pets.

Common Diseases

  • Ichthyophthirius multifiliis (Ich): This parasitic disease manifests as white spots on the fish’s body and fins. It’s highly contagious and can lead to respiratory distress.
  • Fin Rot: Often a result of poor water quality, this bacterial infection causes fraying or disintegration of fins. It’s indicated by a milky or ragged appearance at the edge of the fins.

Treatment Options

  • Medication: Specific to the diagnosed disease, such as antiparasitic treatments for Ich or antibacterial medicine for Fin Rot. Always follow the recommended dosage and treatment duration.
  • Water Quality: Improving tank conditions often helps support recovery. Regular water changes and proper filtration are key components.

Quarantine Procedures

  • Separation: New or sick fish should be isolated in a quarantine tank to prevent the spread of disease.
  • Observation: Monitor fish for a minimum of two weeks to ensure they show no signs of disease before introducing them to the main tank.

Feeding and Nutrition

Proper feeding and nutrition are crucial for the health and growth of your aquarium fish. Your fish require specific diets based on their natural habitats and feeding habits to stay vibrant and active.

Fish Foods

Omnivores: These fish need a balanced diet of plant and animal-based foods. Commercial flakes or pellets designed for omnivores are suitable, ensuring a mix of proteins, carbohydrates, and fats.

Carnivores: Specialized foods such as frozen or live prey including bloodworms, brine shrimp, or krill provide the necessary proteins and fats these fish require.

Herbivores: Algae wafers and spirulina-based foods are ideal, as these fish need a diet rich in plant material to aid their digestion and fulfill their nutritional needs.

Feeding Schedules

  • Daily Feedings: Most fish thrive on being fed once or twice a day. Small, consistent quantities are preferable to prevent overfeeding and maintain water quality.
  • Varied Schedule: Some species may require less frequent feeding or specific feeding conditions, such as nocturnal feedings for certain nocturnal species.


For a fully-balanced diet, especially in planted tanks or specialized fish species, supplements might be necessary.

  • Vitamins: Can boost overall health and are often added to foods or the water directly.
  • Minerals: Specific minerals like calcium or magnesium might be needed, particularly for invertebrates or fish that are used to hard water environments.

Aquarium Design

When designing your aquarium, careful consideration of the theme, placement, and selection of decorations is crucial for both the health of its inhabitants and aesthetic appeal.

Themed Aquariums

Themed aquariums can range from replicating a natural habitat to an artistic creation. You might choose a biotope theme to mimic the natural environment of specific fish species or opt for a fantasy setting. Select live plants, substrates, and decorations that align with your chosen theme for a cohesive appearance.

Aquarium Placement

The placement of your aquarium significantly affects both its visual impact and the well-being of your aquatic life. Ensure it is located away from direct sunlight to prevent algae growth and maintain a consistent temperature. It should be on a stable surface where it can be properly supported and easily accessed for maintenance.

Decor Selection

When selecting decor for your aquarium, consider both functionality and style. Use rocksdriftwood, and live plants not only as design elements but also to provide hiding spots and help maintain water quality. Choose items that are safe for your aquatic creatures and won’t alter the water chemistry. Such as non-toxic, smooth-edged items that are free from sharp points that could harm your fish.

Water Chemistry

Understanding water chemistry is essential for maintaining a healthy aquarium environment. Key factors like pH levels, the nitrate cycle, and hardness and alkalinity must be managed carefully to ensure the well-being of your aquatic life.

pH Levels

pH measures the acidity or alkalinity of your aquarium water. A pH of 7 is neutral, below 7 is acidic, and above 7 is alkaline. Most fish thrive in a range between 6.5 and 8.0. Regular testing and adjustments are necessary to maintain optimal pH levels for your fish species.

Nitrate Cycle

The nitrate cycle, also known as the nitrogen cycle, is a vital process where beneficial bacteria convert toxic ammonia into nitrite and then to less harmful nitrate. A well-established cycle is crucial for reducing toxins in the water. To manage this cycle:

  1. Use a cycling aid or introduce hardy fish.
  2. Test water parameters regularly.
  3. Perform partial water changes as needed.

Hardness and Alkalinity

General hardness (GH) indicates the concentration of magnesium and calcium in water, influencing fish health and biological processes. Carbonate hardness (KH), or alkalinity, affects the water’s buffering capacity against pH fluctuations. Ideal GH levels vary by species, but a KH of 8-10 °dKH helps maintain a stable pH.