July 30, 2025

Founders Message - Aquarium Safety

This is a newsletter that focusses on helping new aquarists get started and remain successful with the enchanting world of keeping freshwater tropical fish alive over the long term.  It is in the very beginning where novice aquarists most often make mistakes and the repercussions can be felt for  very long time in the tank.

Aquarium safety comes in two basic areas.

The first is the external area around the aquarium.  The area around the aquarium can become a problem when the tank is not properly supported on a special aquarium manufactured aquarium stand, or located nthe wrong place, such as on a floor away rom  supporting wall that allows the tank to move as people walk by and the floor sways.  The location also should be somewhere that no sunlight can directly hit the aquarium glass.  The aquarium installation should always be placed away from hot or cold air ducts to ensure the temperature is not impacted by their use.

Other important external factors include the activity around the aquarium,  It should be placed away from the general activity of the home so that sudden movements by the people in the home do cause sudden movements that can scare timid fish. Ideally the tank should be in a quiet location where it can be easily observed in a quiet area that does not affect the way the fish live  

The second area of safety concerns is inside the aquarium, ensuring that the tank's habitat is safe for the fish.  The most important aspect of fish safety is to ensure that the community that is established has a good chance of being compatible. In this aspect, the advice and counsel of knowledgeable employees at a local live fish store is invaluable.  If the wrong fish are selected, the chances of death in the new community is quite high.  Careful thought must be given to the selection of species that will be put together.  One mistake can cost the rest of the community until there is only one left swimming in the aquarium.  If you are shooting for an active, colorful living picture, that can be a huge disappointment.

All aquariums age and require proper maintenance, one of the most effective ways to keep the habitat safe for the fish is to create and maintain a proper maintenance schedule.  The water should be kept at a determined level at all times, so evaporation should be replaced with safe, treated tap water. If there is either chlorine or chloramine in the municipal water supply, it should be eliminated by proper water conditioning products.  If the house is old or some of the water is coming from wells, the conditioner should also be able to remove and chelate heavy metals before they are added to the aquarium. 

While evaporation replacement is important, you must also have a regular scheduled water change routine.  Any water you use to replace evaporation will include a number of other components along with the actual H2O component.  These trace elements will start to concentrate over time since the water that evaporated was pure, and the replacement has added components. It is important to remove them to keep them under control. 

In addition, the actual life processes of the fish and other biological components will add nitrate to the water over time.  While this compound is relatively harmless, being the final by-product of the nitrogen cycle where ammonia is produced by the fish and bacteria then broken to nitrite and finally to nitrate, it still can cause problems for the fish if it is not diluted by proper water changes.

There are other safety related issues when working in the aquarium.  Soap is a killer of fish, you should never have any soap or hand lotion residue on your hands or arms. Always thoroughly rinse your hands and arms with fresh clean water with no additives before placing your hands in the aquarium for any reason.

In some cases decorations must be moved around the substrate.  This can be to accommodate new fish being added so you might want to disturb the established territory of the fish already there to allow new and somewhat stressed additions to be able to slip in without disturbance while the older ones fight to secure their territory again.

No matter the reason, if decorations must be moved, concentrate on doing the job, while rocks and other decorations may feel much lighter since the water is buoying them somewhat, they are still as heavy as outside the tank, so if one is dropped it can easily break the glass bottom.  Keep your mind strictly on the job at hand when moving ornaments to avoid a true disaster should a rock drop with all its weight on the bottom or side. 

The Red-Tailed Shark (Epalzeorhynchos bicolor)

The red-tailed shark (Epalzeorhynchos bicolor), despite its common name, is not actually a shark at all. This striking freshwater fish belongs to the Cyprinidae family, making it a close relative of minnows and carp. Native to the clear streams and river basins of Thailand, this species has become increasingly rare in the wild due to habitat destruction and is now considered critically endangered in its natural range. Fortunately, captive breeding programs have made it widely available in the aquarium trade, where its dramatic coloration and active behavior have made it a popular choice among hobbyists.

Physical Characteristics and Identification

The red-tailed shark's appearance is nothing short of spectacular, featuring a velvety black body that provides a stunning contrast to its vibrant crimson tail fin. Adult specimens typically reach lengths of 4 to 6 inches in captivity, though wild individuals have been known to grow slightly larger. The body is torpedo-shaped and streamlined, perfectly adapted for navigating swift currents in its native habitat. The dorsal fin stands tall and triangular, often edged with white, while the pectoral fins are transparent with subtle hints of orange. The fish's downturned mouth, equipped with small barbels, reveals its bottom-feeding nature and helps distinguish it from similar-looking species.

Natural Habitat and Distribution

Originally found in the Chao Phraya River basin in Thailand, the red-tailed shark inhabited clear, well-oxygenated streams with rocky or sandy substrates. These waterways typically featured moderate to strong currents, abundant vegetation along the banks, and numerous hiding spots among submerged logs and rocks. The species thrived in waters with temperatures ranging from 72 to 79 degrees Fahrenheit and slightly acidic to neutral pH levels. Sadly, dam construction, agricultural runoff, and urban development have decimated wild populations, with the species disappearing from most of its historical range by the 1990s.

Behavior and Temperament

Red-tailed sharks are known for their territorial and somewhat aggressive nature, particularly toward their own species and similar-looking fish. In the wild, each individual maintains a territory centered around a favored hiding spot or feeding area, which it defends vigorously against intruders. This territorial behavior becomes more pronounced as the fish matures, with juveniles being relatively peaceful compared to adults. They are most active during dawn and dusk, spending much of their time grazing on algae and searching for small invertebrates along the substrate. Despite their aggressive reputation, these fish are actually quite shy and require plenty of hiding places to feel secure.

Dietary Requirements

In their natural habitat, red-tailed sharks are omnivorous bottom-dwellers with a diet consisting primarily of algae, periphyton, small crustaceans, and insect larvae. They use their specialized mouth structure to scrape algae from rocks and submerged surfaces, playing an important ecological role in their ecosystem. In captivity, they readily accept a variety of foods including high-quality sinking pellets, algae wafers, blanched vegetables such as zucchini and cucumber, and occasional treats of bloodworms or brine shrimp. A varied diet ensures optimal health and helps maintain their intense coloration. It's important to note that while they do consume algae, they should not be relied upon as the sole algae control in an aquarium.

Reproduction and Life Cycle

Breeding red-tailed sharks in captivity presents significant challenges, and most specimens in the aquarium trade come from commercial breeding facilities in Southeast Asia that use hormone injections to induce spawning. In nature, reproduction likely coincides with seasonal changes in water flow and temperature. The species is believed to be an egg-scatterer, with females releasing hundreds of eggs during spawning events. Sexual dimorphism is subtle, with females typically being slightly larger and fuller-bodied than males. The lifespan of a well-cared-for red-tailed shark can exceed 8 years in captivity, with some individuals reportedly living over a decade.

Aquarium Care Considerations

Keeping red-tailed sharks successfully requires careful attention to their specific needs. A single specimen requires a minimum tank size of 55 gallons, with larger aquariums needed if housing multiple fish or a community setup. The aquarium should feature strong filtration to maintain high water quality and create the water movement these fish prefer. Decorations should include caves, driftwood, and rock formations to provide territories and hiding spots, while leaving ample open swimming space. Water parameters should be maintained at temperatures between 72-79°F, pH of 6.5-7.5, and moderate hardness. Regular water changes of 25-30% weekly are essential for their long-term health.

Conservation Status and Future Outlook

The wild population of red-tailed sharks faces a precarious future, with the species listed as Critically Endangered by the IUCN. Some experts believe it may already be extinct in the wild, though unconfirmed sightings occasionally surface. Conservation efforts have been hampered by political instability and lack of funding in the species' native range. The thriving captive-bred population serves as an inadvertent ark for the species, though these fish have been bred in captivity for so many generations that their genetic diversity may be limited compared to their wild ancestors. Reintroduction programs have been discussed but face numerous challenges, including the degraded state of their natural habitat and the uncertain genetic suitability of captive-bred stock.

The red-tailed shark's story serves as both a cautionary tale about habitat destruction and a testament to the aquarium trade's potential role in species preservation. While hobbyists can enjoy these beautiful fish in their home aquariums, it's important to remember that each specimen represents a species teetering on the brink of extinction in the wild. Responsible aquarium keeping, including proper research before purchase and commitment to long-term care, helps ensure that future generations will continue to marvel at these remarkable fish, even if only in captivity.

Regular water changes are crucial for keeping your aquarium healthy and safe for aquatic life.

Using a gravel cleaner removes trapped waste from the substrate, improving water clarity and stopping harmful chemical buildup.

Fish waste and leftover food naturally boost nitrate levels over time.

Consistent water changes, such as a 10–20% weekly routine, help reduce nitrates and lower stress for your fish.

Always treat replacement water to remove chlorine and match the tank's temperature and pH before adding it.

Limit each change to no more than 33% of the water to keep the biological filter stable.

Never replace all the water at once, as it can harm beneficial bacteria and disrupt your tank’s balance.

Adding live plants like hornwort or duckweed also helps control nitrates, ensuring a cleaner, more vibrant aquarium community.

Q: How often should I perform water changes in my tropical aquarium?

A: Perform a 20-25% water change bi-weekly for most tropical community tanks. This removes waste products and replenishes essential minerals while maintaining stable water parameters.

Q: How many tropical fish can I keep in my tank?

A: Follow the general rule of 1 inch of fish per gallon of water for small community fish. However, consider factors like filtration capacity, fish activity levels, and adult size when stocking.

Q: What are some signs my tropical fish might be sick?

A:Signs of illness in tropical fish include loss of color, loss of appetite, lethargic or abnormal behavior, spots or fungus on body, and abnormal swimming patterns. If you notice any of these signs, it could mean your fish is sick and needs treatment.

A clean aquarium is vital for the health of your fish and the balance of their ecosystem.

Always maintain proper hygiene and safety to protect both your aquatic life and yourself during cleaning.

Rinse your hands thoroughly with fresh water before touching anything in the tank—avoid any trace of soap or lotion, as even small residues can harm fish.

For added protection, wear shoulder-length rubber gloves, especially if you have cuts or scrapes on your skin.

This barrier shields you from potential bacteria and keeps the aquarium free from outside contamination.

Always turn off and unplug equipment like filters and heaters before starting maintenance.

This simple step prevents accidental electric shock and ensures safe cleaning.

Following these easy practices helps create a healthy habitat while keeping you safe.

What unique behavior is often noticed about the Red Tailed Shark in a community aquarium?

Rearranging aquarium decorations can help new fish settle in by breaking up established territories and encouraging all inhabitants to adapt.

However, ornaments and rocks retain their full weight underwater, even if they feel lighter due to buoyancy.

Dropped decorations can crack or shatter aquarium glass, creating major risks for your setup.

To keep your tank safe, always handle items with dry hands and consider using both hands for heavier pieces.

Whenever possible, remove the decoration from the water before moving or cleaning it.

Examine each item for sharp or rough spots that could injure your fish, and use sandpaper or a file to smooth them out if needed.

Careful handling protects both the health of your fish and the integrity of your aquarium.

Maintaining a healthy freshwater aquarium is vital for your tropical fish’s well-being.

Mechanical filter media play a crucial role by physically removing debris and keeping water clear.

Polywool, or filter floss, captures even the smallest particles and fits a variety of filtration systems, but needs frequent replacement to prevent clogging.

Foam blocks filter debris and also provide a home for beneficial bacteria, aiding both mechanical and biological filtration processes.

Maintaining foam blocks is simple—just rinse them in aquarium water to retain their helpful bacteria colonies.

Ceramic rings and sintered glass are other popular choices, thanks to their porous surfaces that trap particles and promote bacterial growth.

Select media types based on your aquarium’s needs and filtration equipment to maximize water quality and support your fish’s health.

Maintaining ideal water temperature is essential for healthy aquarium life.

Most aquarists rely on heaters, with bimetallic strip and electronic thermostat heaters as the chief options.

Bimetallic heaters use two metals that bend with heat changes, activating or shutting off the circuit.

They’re affordable but often less precise as they age.

Modern electronic thermostat heaters use digital sensors for consistent accuracy, often featuring digital displays and programmable controls.

Chillers, designed to cool water, are rare in home setups because of their expense and high energy use.

They're usually reserved for specialized public aquariums or cold-water species that require exact cooling.

Innovations like Wi-Fi-enabled smart heaters now let hobbyists monitor and adjust temperatures remotely, ensuring stability for aquatic pets.

For most homes, electronic heaters provide the best mix of precision and convenience.

AquaScaping - Time Lapse Creation

The Red Tailed Shark is known for its territorial nature. Despite being a generally peaceful species, it often claims a certain area of the aquarium as its own and can show aggression towards other fish that enter this space.