Why Do My Bristlenose Plecos Keep Dying? Common Causes & Solutions

Last Updated on February 27, 2022 by cmoarz

A Bristlenose Pleco is a common name for the Hypostomus plecostomus fish. They are a type of suckerfish that is often kept as a tank cleaner. They are generally hardy fish, but there are some things that can cause them to die. So why do my bristlenose plecos keep dying?

This article will discuss some of the common causes of Bristlenose Pleco death, as well as solutions to prevent it.

What causes a pleco to die?

Temperature is too high: As far as most common reasons plecos die, this one is it. If the water temperature in your tank is too high, your pleco will die.

This can happen quickly, or over time, but either way it’s not good news for your fish.

Plecos are extremely sensitive to the temperature of the water and if it gets too high, they will die.

Poor water quality: Poor water quality is definitely up there in the list of common causes of Bristlenose Pleco death. The main culprits are high levels of ammonia and nitrate, which can cause serious health problems in fish.

It’s important to maintain your water quality by doing regular water changes and using a good quality filter.

Vacuuming the substrate often and having live plants will also help keep water at a manageable quality for longer periods of time.

Inadequate diet: Many people mistakenly believe that plecos can live just off the algae they clean from the tank. This isn’t true, and an inadequate diet can lead to malnutrition and death.

Plecos need a varied diet that includes both algae and protein foods.

Housing problems: Bristlenose plecos need a minimum of 20 gallons to feel “comfortable” in their environment. Usually, this is mixed with an abundance of live plants and hardscapes, such as driftwood, sticks, and smooth rocks.

Anything less than ideal can lead to stress, which will ultimately lead to death.

Plecos also tend to stay low to the ground and suction onto objects in the tank. If any of these things are sharp, such as pointy gravel or rough hardscape, it can lead to injury.

Injuries often quickly lead to infection and death.

Parasites and diseases: Bristlenose plecos are pretty vulnerable to internal parasites due to their bottom-feeding nature.

When parasites are introduced into your aquarium, bottom feeders are often the first to hit struck.

Symptoms of parasites include loss of appetite, lethargy, and white spots on the body.

These parasites can quickly take over and cause death.

Medication Complications: Overdosing or miss-dosing medications is another common cause of Bristlenose Pleco death.

Many medications are highly toxic to fish and can cause serious health problems, even death.

It’s important to always read the label and dosage instructions carefully and to never mix medications without consulting a professional.

Before medication, you should always do deep research on the effects the medication has on anything in your tank including your plecos.

Solutions for Preventing Bristlenose Pleco Death, How do you keep plecos alive?

Lower the temp: Bristlnose plecos water temp should be around 28c (82.4f). Prolonged time at higher temperatures can easily lead to discomfort for the pleco, stress, and eventually death.

It can be difficult to lower ambient temperature in certain parts of the world without expensive equipment, However, We recommend evaporation fans. We’ve found they work really well at lowering the temperature of an aquarium a few degrees with almost no investment at all. Check out this one as an example of ones we’ve used in the past.

Improve water quality: This probably goes without saying, but keeping your water quality in check is one of the most important things you can do to keep your fish healthy, including plecos.

Regular water changes, using a good quality filter, and vacuuming substrate often are all key.

Avoid overfeeding that could cause your tank balance to change and live plants help with this also.

Ammonia and nitrite levels should be 0 and nitrates should be kept under 10ppm. Live plants are excellent at helping to keep nitrate levels down as they consume them as part of their natural photosynthesis process.

Provide an adequate diet: As mentioned before, plecos need a varied diet that includes both algae and protein foods.

Many people mistakenly believe that algae are all a pleco needs to live, but this isn’t the case.

Protein should make up about 20% of their diet. Sinking shrimp wafers (orange ones) are an excellent source of protein and often come side by side with the algae wafers you should be feeding them as well.

Don’t rely on them being able to scavenge for food off the bottom of your tank: This is a common misconception as well.

While they will scavenge for food, it’s important to provide them with an adequate diet to ensure they’re getting all the nutrients they need.

Create a suitable housing environment: A happy environment makes a happy fish.

Driftwood, sticks, and smooth rocks create a more natural habitat that the pleco would love to live in. Lots of things to suck on.

Make sure the tank is large enough for them to swim around in and doesn’t have any sharp edges that could lead to injury.

Those rock caves (the salt and pepper-looking ones) are terrible for plecos, avoid them. They are sharp and rough.

The pleco will have a hard time sucking on them and it could cause them to be injured in the process.

Lots of live plants are recommended for places to hide in and they will love the extra algae growth.

The plants will also help keep your water quality up by consuming nitrates.

Treat for parasites and diseases: Parasites can be extra nasty and diseases can quickly take down your fish, including plecos.

There are many different treatments available on the market, but it’s important to do your research first to see which is the best fit for your tank.

Many of these medications are highly toxic to both fish and plants, so be very careful when using them.

Identifying which parasite or disease your pleco has is out of the scope of this article, however, you will need to narrow it down in order to properly treat it.

If you don’t feel comfortable doing so yourself, Your local fish store may be able to help you diagnose and treat the problem.

Hopefully, these tips will help you keep your bristlenose pleco happy and healthy for years to come. If you have any questions or would like more information, please leave a comment below and we’ll do our best to help. Thanks for reading!


Owner of AquariumGravel.com and also owner of actual Aquarium Gravel believe it or not! ;). Setting up beautiful aquarium sceneries and habitats since I was very young. Enjoy!