Blue Phantom Pleco: Our Handy, In-depth Aquarists’ Guide

Alison Page

Alison Page


Blue Phantom Pleco

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Blue Phantom plecos are attractive tropical fish that can keep your aquarium tidy by grazing on algae.

These bottom-dwelling, active fish from Venezuela are straightforward to care for and are pretty long-lived too, Making them an excellent option for a large community tank.

Read this comprehensive guide to learn everything you need to know about caring for the beautiful Blue Phantom pleco.

Blue Phantom Pleco – Overview

Blue Phantom Pleco Info
Scientific Name:Hemiancistrus sp. L128
Common Name (species):Blue Phantom pleco
Origin:South America, Venezuela
Diet:Omnivorous fish: eats green algae, bloodworms, brine shrimp, veggies
Care Level:Intermediate
Activity:Bottom-dwelling, nocturnal scavenger
Lifespan:Between 10 and 15 years
Tank Level:Bottom
Minimum Tank Size:40 gallons
Temperature Range:Tropical 77° to 86° Fahrenheit
Water Hardness:2 - 12 dGH
pH Range:6.0 to 7.0
Filtration/Flow Rate:Likes well-oxygenated, well-filtered water and a moderate flow rate
Water type:Freshwater
Breeding:Rarely bred in captivity but an egg-laying, cave-spawner
Compatibility:Peaceful with most species of sociable fishes.
OK for Planted Tanks?:No


The Blue Phantom pleco (scientific name: Hemiancistrus sp. L128) is a type of catfish that belongs to the Loricariidae family. This species of pleco is only found in a specific region of the South American continent, being native to the Rio Orinoco in Venezuela downstream from Puerto Ayacucho.

This catfish species lives in the river rapids, hiding under boulders and rocks during the day and feeding on small insects, insect larvae, worms, algae, and plant matter.

Blue Phantom plecos are popular with hobbyists for their distinctive blue-black coloration and striking white spots and patterns. However, because of their specific habitat requirements and potential conservation concerns related to over-fishing for the trade, we encourage you to buy a captive-bred specimen to help preserve wild populations.

The Loricariidae catfish family is usually referred to as armored catfish since their bodies and suckermouths are covered with protective bony plates. In addition, these fascinating fish have a modified vascularized stomach, meaning they can breathe atmospheric air when needed.


The main characteristic of Blue Phantom plecos is their dark blue or blackish body coloration, which can vary a little depending on the individual fish, water conditions, and lighting.

The fish’s body sports distinctive white or pale-colored patterns, creating a stark contrast against the dark background body color.

This species of fish can sometimes be mistaken for a similar-looking pleco variety, Hypostomus adiposus, which is also commonly referred to as the Blue Phantom pleco. Although that species has a similar dark body color with white or lighter markings, there can be differences in their patterns and color intensities.


The Blue Phantom plecostomus typically grows to around 7.5 inches long in captivity and is a pretty slow grower.

Life Expectancy

Blue Phantom plecos have a long lifespan, surviving for 10 to 12 years in captivity and living for up to 15 years in the wild. Of course, the captive fish’s health and longevity depend largely on the diet and living conditions you provide for them.

Activity Level/Temperament

Like many other pleco species, Blue Phantom plecos are primarily nocturnal, meaning they are more active at night than in the daytime. In a well-lit aquarium, you might see the fish hiding in caves or under driftwood during the day, coming out in the evening to explore and search for food.

Although generally peaceful, especially with non-similar-looking species, Blue Phantom plecos can be somewhat territorial, especially toward other plecos or similar-looking fish. For that reason, it’s a good idea to provide the fish with multiple hiding spots in the form of caves, driftwood, or PVC pipes to minimize territorial squabbling.

Aside from territorial tendencies towards similar species, the Blue Phantom pleco is generally non-aggressive and can live harmoniously with a wide range of peaceful tank mates.

Compatibility and Tank Mates

The Blue Phantom pleco is a peaceful creature that can make a good addition to a community aquarium. These large fish won’t view small fish species or invertebrates as a food source, and their armored scales keep the plecos protected from curious tankmates. That said, fin nippers should be avoided, as they can hassle the plecos and stress them, leaving the Blue Phantoms vulnerable to disease.

As mentioned above, Blue Phantom plecos can be territorial with their own kind and with similar-looking fish, so I would avoid keeping multiple Blue Phantoms unless you buy two juveniles that have been raised in the same tank.

Note that Blue Phantom plecos will try to eat the slime coating of other fish, so large, slow-swimming fish, such as Discus and Angelfish, should be avoided.


As with any fish species, feeding your plecos a correct, high-quality diet is critical for their well-being, health, and longevity. So, although it can be tempting to save money by buying cheap food, I recommend that you go for the best quality food you can afford for your Blue Phantom plecos.

What To Feed Your Blue Phantom Plecos

Blue Phantom plecos are primarily herbivores and will consume a varied diet that can include algae wafers, blanched vegetables (like zucchini and spinach), and some high-quality sinking pellets. They also appreciate occasional protein in the form of brine shrimp, bloodworms, tubifex, and insect larvae.

Although your plecos will happily eat live foods, I recommend using frozen meaty proteins instead since live food often comes with an unwanted cargo of parasites and bacteria that could make your fish sick.

How Much and How Often To Feed

When feeding your Blue Phantom plecos, remember these fish are nocturnal, so it’s best to feed them just before lights out at the end of the day, and if you have moonlighting, you’ll get to see more of them.

Plecos eat algae, so if you have a lot of it growing in your tank, be careful not to overfeed your fish by offering them supplementary foods they actually don’t need. Unless you have a cleaning crew of snails and shrimp in your aquarium, uneaten food will fall onto the substrate, where it will gradually rot, polluting your water.

Ideally, you should feed your fish only what they will clear within a few minutes so as to avoid overfeeding them.

Tank Requirements

Blue Phantom Pleco

Plecos are hardy and relatively straightforward to care for, although they do require weekly water changes and stable water parameters to stay healthy and thrive.

Tank size

Since Blue Phantom plecos can be territorial in nature, we recommend a larger tank of at least 40 gallons.

As these fish are bottom-dwellers, a shallow rectangular aquarium is the best choice of shape rather than a tall, deep one. Although plecos don’t jump, a tank with a lid or cover slide is the best choice. That can prevent dust and debris from falling into the water and contaminating it and helping to prevent evaporation, which could lead to unstable water parameters.

Tank Setup


Blue Phantom plecos are primarily bottom-dwellers that like to burrow, so a soft, sandy substrate is the best choice for them, perhaps with a few smooth pebbles mixed in.

Lighting and Decoration

Blue Phantom plecos are nocturnal fish that will avoid brightly lit areas of the aquarium during the day, so regular LED lighting is fine for them. You might also want to include moonlighting, which will enable you to watch your fish after the main lights go out and they come out to feed.

These fish like to hide underneath piles of rocks, overhangs, or in caves close to the filter outflow, so the ideal decor for a tank with Phantoms would be tall piles of boulders and rocks and a few branches and some driftwood.

Live Plants

Although you can keep Blue Phantom plecos in a planted aquarium, they will tend to damage and uproot live plants.

However, if you want to add live plants to your aquascape, floating varieties can help to bring valuable shade and keep the tank lighting dim, which suits these nocturnal fish. You could also consider keeping live plants in clay pots so that their roots aren’t dislodged by the fish.

Habitat Requirements


Although wild plecos prefer turbulent water conditions, you don’t need a powerhead to create waves in your aquarium. As long as you have an efficient filtration system that’s the correct size for your tank and you maintain high water oxygenation using air stones or bubbler devices, the Blue Phantom pleco can tolerate living in an environment with a medium current.

I recommend using a couple of HOB filters or a robust canister filter, depending on your tank’s capacity and whether you also have a powerhead. Dirty water and low oxygen conditions will cause these fish a great deal of stress, which will significantly reduce their life expectancy.

Water Parameters

Blue Phantoms prefer stable, tropical water temperatures between 77 and 86°F so you will need an aquarium heater. The fish prefer slightly soft water with a hardness of 2 to 12 KH and a neutral pH of 6.0 to 7.0.

Tank Maintenance

These fish are voracious eaters and generate a lot of waste. So, you’ll need to perform weekly water changes to keep the environment clean and nitrates at an acceptable level.

In addition, rinse the filter media in tank water to remove sludge and gunk that would otherwise prevent the water from circulating efficiently.

Health and Disease

Blue Phantom plecos are generally healthy creatures that don’t suffer too much from diseases, although they do sometimes pick up parasites and bacterial infections, generally because of dirty water conditions. So, by keeping on top of your tank maintenance tasks, you can help to keep your plecos disease-free.

That said, a big problem for plecos is starvation, especially if you don’t have much or any green algae growing in their aquarium, so you must supplement the plecos’ diet accordingly.


In nature, Blue Phantom plecos are cave-spawners, but there are few reports of them breeding successfully in captivity. Unfortunately, that means most of the fish you find in the trade are wild-caught, although some come from commercially operated breeding farms.


Blue Phantom plecos are one of the more unusual pleco varieties, so you won’t find one in every high street fish store. However, they do come up occasionally, and you can buy them online for around $70, depending on the size and coloration of the specimen.

Final Thoughts

The Blue Phantom pleco is a beautiful, unusual pleco variety that you don’t often find in fish stores. These are fairly hardy fish that can do well in a large, well-maintained tank with some peaceful tank mates, although they can be territorial with their own kind and other similar-looking species.

Like all plecos, the Blue Phantom is an omnivorous bottom-dweller, enjoying a diet of meaty protein and vegetable matter, and they’re also algae-eaters, helping to keep your tank clean and tidy.

Aside from their territorial nature, the main drawback to these plecos is that they are not plant-safe and tend to uproot and eat tender live plant species.

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