Blue Phantom Pleco L128 (Hemiancistrus sp.) – 3–10cm Size Grades

Blue Phantom Pleco L128 is an undescribed Orinoco-basin loricariid sold in the aquarium trade under the provisional name Hemiancistrus sp. L128. Its exact taxonomic placement is still unresolved, so this page treats Hemiancistrus as a useful trade-level anchor rather than a formally confirmed species name.

One quantity supplies one unsexed fish in the selected approximate size grade. Current Shopify variants range from 3–4cm to 7–10cm. These are dispatch grades; they should not be confused with adult size.

Blue Phantom Pleco L128 at a glance

Why the scientific name is cautious

L128 remains an undescribed L-number catfish. It is widely traded as Hemiancistrus sp. L128, but specialist sources note that even the generic placement is tentative. This listing therefore keeps the L-number and common name prominent rather than pretending the fish has a fully resolved formal species identity.

Do not confuse L128 Blue Phantom with L200 Green Phantom. They are closely similar Orinoco forms but have different trade identities and colour appearance.

Aquarium size and setup

Use a mature aquarium of around 250 litres or more, ideally with at least 120cm of length and strong filtration. Some adult-size references place L128 near 20cm, while others report 25–30cm, so a conservative aquarium plan is safer than designing around the smallest published number.

Create strong oxygenation, smooth circulation, several caves and substantial rock or wood structure. Leave enough open floor area for feeding and maintenance. Blue Phantoms can become territorial around caves, especially with other loricariids, so provide more refuges than plecos.

Use smooth sand or rounded substrate and avoid sharp edges. A darker setting often improves confidence and makes the blue-grey body and pale spots more visible.

Water quality

Keep the water warm and oxygen-rich at roughly 24–28°C and pH about 5.5–7.5. Ammonia and nitrite should remain at zero, with nitrate controlled through measured feeding and regular water changes. A powerhead or well-positioned filter return can improve flow along rockwork without turning the entire aquarium into a harsh jet.

Feeding

Blue Phantom Plecos graze biofilm and soft algae, but they are not self-sufficient clean-up animals. Feed them deliberately. Use quality sinking omnivore or algae wafers, suitable vegetables and occasional protein-rich foods such as appropriately sized frozen invertebrates or carnivore pellets.

Feed after lights dim if the fish is shy and make sure food reaches its cave area before faster tank mates take it. Remove persistent vegetables and rich leftovers before they degrade water quality.

Tank mates

Choose peaceful mid-water fish too large to be accidental prey and compatible with the same warm, oxygenated water. Medium tetras, rainbowfish and other calm community fish can work well. Other plecos require caution because cave competition can become intense.

Avoid aggressive cichlids that repeatedly invade caves or damage fins. Shrimp may be disturbed or eaten opportunistically, especially smaller individuals, so do not treat L128 as guaranteed shrimp-safe.

Blue Phantom Pleco questions

What is the scientific name of L128?

It is an undescribed L-number catfish commonly traded as Hemiancistrus sp. L128. The exact taxonomic placement remains uncertain.

How large does a Blue Phantom Pleco grow?

Published hobby and specialist estimates vary. Plan conservatively for roughly 20–30cm rather than assuming it will remain around 15–18cm.

What tank size is recommended?

Use around 250 litres or more with a long footprint, strong filtration and several caves. More room is advisable with additional bottom dwellers.

Does L128 eat algae?

It grazes biofilm and soft algae, but it still needs deliberate sinking food, vegetables and protein variety.

What temperature does it need?

Keep it around 24–28°C with strong oxygenation and stable water quality.

Can I keep more than one pleco?

Possible in a much larger aquarium, but cave competition can be strong. Provide multiple separated refuges and monitor access to food.

Is L128 the same as Green Phantom Pleco L200?

No. They are similar Orinoco L-number forms but have separate trade identities and should not be merged casually.

Can I choose a male or female?

No sex is guaranteed by the current size variants.