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Why Do My Red Tail Sharks Keep Dying? (8 Possible Reasons)

Why Do My Red Tail Sharks Keep Dying? (8 Possible Reasons)

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This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addition, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

So you just bought a Red Tail Shark and took it home to the aquarium, only to find it dead a few days later.

Even worse, you try to get another shark. However, the new fish meets the same fate, which leaves you wondering “why do my red tail sharks keep dying?”

Red Tail Sharks are hardy fish but they can still die if the tank doesn’t meet the required conditions to survive. Poor filtration, high Nitrate, diseases, tank mate conflicts, and other factors could also kill a Red Tail Shark.

In this guide, we’ll take a closer look at some of those reasons, and how to avoid them in the future to extend your fish’s life!

1 – Nitrates and Nitrite Concentration Are Too High

Red Tail Sharks don’t have regular scales, so they can be quite sensitive to the concentration of some ions in the water, such as nitrates and nitrites.

Although nitrates aren’t highly toxic to Red Tail Sharks, they can be silent killers when their concentration exceeds normal limits.

As they enter the fish’s bodies, they slowly spread into the tissues and wear down their immune system.

This makes the fish prone to diseases that could be fatal. Ideally, Nitrates concentration in water shouldn’t exceed 20 parts per million (ppm).

On the other hand, nitrites are more poisonous than nitrates because they bind to the fish’s hemoglobin, which reduces its oxygen-carrying capacity, causing the fish to suffocate, even if oxygen levels in the tank are stable.

For that reason, nitrite levels should be checked regularly to make sure that they’re below 0.75 ppm.

To reduce nitrate and nitrite concentration, use better filters and do a 25% water change periodically.

2 – The pH Level/Hardness Is Out of Range

Red Tail Shark can withstand a wide pH range of 6.8 to 7.5 and water hardness of around 5 to 15 dH.

While it can also survive briefly outside these ranges, the fish would be extremely uncomfortable and prone to serious diseases if you leave them for a long time.

For that reason, you should always use a pH and water hardness detecting tool and adjust them with your aquarium care kit whenever they’re out of range.

3 – Water Temperature Is Too High or Too Low

As a tropical fish that originally hails from Thailand, Red Tail Sharks do best in relatively warm climates where water temperature ranges between 72 °F to 79 °F (22.2 °C to 26.1 °C).

If you live in a relatively cold area where temperatures drop significantly at night, Red Tail Sharks may end up dying pretty quickly due to stress.

This happens because their metabolism slows down in cold temperatures, which affects their vita processes and makes them prone to hypothermia and malnutrition.

You can easily track and adjust the temperature of the tank by using a proper aquarium heater with a built-in thermostat.

4 – Excessive Feeding with Poor Filtration

As previously established, changing the water frequently is necessary to reduce the concentration of nitrates and nitrites in the water.

However, they’re not the only toxins that could harm a Red Tail Shark. If you end up giving your fish too much food, the leftovers will decompose into harmful toxic compounds that can heavily impact the fish’s health.

For that reason, you need to apply a decent filter to the fish tank to make sure that all the water is cycled and free from harmful toxins.

5 – Overcrowding and Small Tank Size

Red Tail Sharks aren’t the largest aquarium fish species, as they only grow to about 6 inches. However, they still need plenty of space to live comfortably in a fish tank.

At first glance, 20 to 35 gallons may look like a suitable capacity for the fish tank. However, many breeders found that any tank smaller than 50 to 60 gallons caused the Red Tail Shark to display signs of distress.

6 – Diseases and Infections (Contamination)

Another factor that many new aquarium owners overlook is the source of water and food used in the tank.

Red Tail Sharks are resistant to many diseases but they’re still prone to bacterial and fungal infections from contaminated water, which causes diseases like ich and fin rot.

If the dead fish show symptoms of these diseases, including white or black spots on the fish’s body, you’ll need to get rid of all the water in the tank and sterilize everything that came in contact with it before getting new fish.

7 – Problems with Other Fish

Despite their small size, Red Tails Sharks are quite territorial and will display aggressive behaviors towards any fish that goes into their territory, such as bullying and chasing across the aquarium.

For that reason, you shouldn’t pair these fish with other species that could put up a fight, as some species may inflict some serious injuries that could prove fatal to the Red Tail Shark.

8 – Tank Decorations and Setup Accidents

Lastly, while buying decorations and equipment for the new tank, you should make sure that they’re safe for your fish.

For example, you should put a guard on the filter to make sure that it doesn’t harm your fish while darting around the tank.

Also, you should install it away from the bottom, as this is where Red Tailed Sharks spend most of their time.

Final Thoughts

This wraps it up for today’s guide that shows you all the common reasons why Red Tail Sharks die suddenly.

As you can see, most of these issues can be measured or tracked, so it’s easy to prevent them in the future once you figure them out!

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