Essential Tropical Fish Species Guide: The simplified guide to identifying, selecting and caring for your tropical fish

Introduction

Tropical freshwater fish are a popular choice for aquarium enthusiasts due to their vibrant colors, unique markings, and diverse behaviors. These fish come from various regions of the world where the water is warm and relatively stable in temperature.

One of the most striking features of freshwater tropical fish is their wide range of colors and patterns. From vivid blues, reds, and yellows to subtle pastels and intricate markings, these fish come in a stunning array of hues.

Different species exhibit fascinating behaviors from spectacular schooling displays to territorial and courtship rituals. These behaviors add life and dynamism to the aquarium.

This book contains the most common species found in most aquatic stores and is by no means exhaustive.

First things to take into consideration are the fish’s adult size, its temperament, compatibility with other tank-mates, and care difficulty. These are indicated in the book.

Temperament

Peaceful: Species in this category are generally non-threatening and have a calm and passive nature. They prefer peaceful coexistence with tank mates and are unlikely to show aggression. Peaceful fish are usually well-suited for community aquariums, as they rarely engage in territorial disputes. Some peaceful species may exhibit reclusive behaviors, seeking hiding spots among decorations or plants..

Semi-Aggressive: Fish in this category are more active and may occasionally display chasing or aggression, especially towards fish with similar shapes or colors. While they can coexist with other tank mates, it is essential to monitor their behavior to prevent potential conflicts. When introducing semi-aggressive species, do so after establishing smaller, more passive fish in the aquarium. Providing ample space and hiding spots can help reduce aggression among semi-aggressive fish.

Aggressive: Species in this category are territorial and bold. They often establish their territories and may defend them vigorously. Aggressive fish should generally be housed with fish that share a similar demeanor and can stand their ground. Keeping them in a species-only aquarium is recommended, as they might not tolerate other fish well. If adding aggressive fish to a display with semi-aggressive tank mates, they should be the last fish introduced to the tank to minimize territorial disputes.

Care Difficulty

Easy: Fish in this category are undemanding and relatively low-maintenance. They have simple feeding requirements and can tolerate a broad range of water conditions. Easy-care fish are ideal for beginners and can adapt well to various environments. Some examples of easy-care fish include popular community fish like guppies, platies, and neon tetras.

Moderate: Fish in this category require a bit more care and attention to thrive. They might have specific feeding preferences, such as preferring live or frozen foods over standard flakes or pellets. Moderate-care fish may also need water conditions that closely resemble those found in their natural habitat, including specific temperature ranges and water chemistry. Providing suitable tank decorations, plants, and hiding spots can create a more comfortable environment for them. Some examples of moderately demanding fish include certain cichlids, rasboras, and dwarf gouramis.

Difficult: Fish in this category demand a higher level of care and attention, particularly regarding water quality and stability. Many of these species have specific feeding, water, and lighting requirements to maintain their health and vibrant colors. Difficult-care fish should only be added to a well-established aquarium that has been running smoothly for several months. Their tank should be equipped with efficient filtration and regular water testing to ensure pristine water conditions. Examples of difficult-care fish include delicate species like discus, some species of angelfish, and certain types of catfish.

Water Parameters

One of the most critical factors in maintaining the health and well-being of your fish is to ensure that their aquarium water meets their specific requirements. Different fish species have varying preferences when it comes to water conditions, including temperature, pH level, hardness, and other factors. Therefore, it is essential to be aware of and maintain the correct water parameters for the species you are interested in keeping. We have included some general water parameters for each species covered in this book. You can test these parameters using a test kit, which is readily available in most pet stores that stock fish. While most aquarium species can tolerate a broad range of water conditions, keep in mind that certain delicate species of fish have very specific water parameter requirements. If you are using tap water, then you will need a water conditioner.

Temperature

Temperature plays a crucial role in the overall health and behavior of fish. Many tropical fish species thrive in water temperatures ranging from 75°F to 82°F (24°C to 28°C).

However, some species might prefer cooler or warmer conditions. For instance, coldwater fish such as goldfish and certain species of tetras prefer lower temperatures around 68°F to 74°F (20°C to 23°C). Use a reliable aquarium thermometer to monitor and maintain a consistent temperature suitable for the specific fish you have..

Fish are cold blooded and are very sensitive to temperature changes and any sudden temperature change can wreak havoc on your fish. Invest in a reliable heater to maintain a stable water temperature.

Water Hardness

Water hardness refers to the concentration of minerals, primarily calcium and magnesium, in your aquarium water. Understanding the two main aspects of water hardness is essential for maintaining a healthy aquatic environment:

Carbonate hardness (KH), often referred to as KH, measures the concentration of carbonate and bicarbonate ions in the water.

KH acts as the main buffering capacity of the water, helping it resist drastic changes in pH levels. When the KH is high, the pH tends to remain stable, which is beneficial for the overall health of fish and other aquatic organisms. A dKH between 4 and 12 is recommended.

General hardness (GH), often referred to as GH, measures the concentration of calcium and magnesium ions in the water.

Different aquatic species have specific preferences for water hardness. Some thrive in hard water, which contains a higher mineral content, while others prefer soft water, with lower mineral levels. GH is typically measured in degrees of hardness (dH), where higher values indicate harder water and lower values indicate softer water.

Both KH and GH levels are usually measured in dKH or dGH (degrees of hardness), with 1 dKH or dGH equivalent to 17.9 ppm (parts per million) of the respective mineral. Purchase a water hardness test kit from a pet store or online retailer.

pH

The pH level of your aquarium water indicates its acidity or alkalinity. Most tropical fish prefer a pH range between 6.5 to 7.5, which is slightly acidic to neutral.

The pH level directly impacts the health, behavior, and overall well-being of the fish. Different species have specific pH preferences based on their natural habitats. Therefore, maintaining the appropriate pH range is crucial to support their biological processes and reduce stress.

Regularly test the pH level and make adjustments if needed to meet the preferences of your fish. The pH is the measurement of relative alkalinity or acidity of the water.

A pH reading of 7.0 is considered neutral.

Lower than 7.0 (down to 0) is acidic.

Higher than 7.0 (up to 14) is alkaline.

Some factors can affect the pH of your aquarium. The pH of your tap water may vary depending on your location and the water source. Some areas have naturally alkaline water, while others may have more acidic water.

The nitrogen cycle, which involves the conversion of ammonia to nitrite and then nitrate, can influence pH levels in the aquarium. Ammonia can make the water more acidic, while nitrates can make it slightly more alkaline.

Some substrates, such as crushed coral or limestone, can increase the pH and hardness of the water, making it more alkaline. On the other hand, driftwood or peat moss can have an acidic effect on the water.

To control pH levels in your aquarium, you can use various methods:

Buffering Substances: Adding commercial pH buffers can help stabilize pH levels and prevent rapid fluctuations.

Driftwood and Peat Moss: If your water is too alkaline, adding driftwood or peat moss can help lower the pH.

Crushed coral or limestone: If your water is too acidic, adding crushed coral or limestone can help raise the pH.

Aeration: Proper aeration can help maintain a stable pH level by releasing excess CO2.

Ammonia, Nitrite, and Nitrate Levels

Regularly monitor ammonia, nitrite, and nitrate levels in your aquarium. Ammonia and nitrite are harmful to fish, and high levels can lead to stress and even death. A well-established aquarium should have undetectable ammonia and nitrite levels. Nitrate is a byproduct of the nitrogen cycle and should be kept at low levels (less than 20 ppm). Perform regular water changes to control these parameters and maintain a healthy nitrogen cycle.

For your tank to be successful, you need to establish the nitrogen cycle.