Rubber Lip Pleco

Chaetostoma formosae

Also known as: Rubbernose pleco, Bulldog pleco, L187B

Water Parameters

• Temperature: 20–25°C
• pH: 6.8–7.8
• Hardness (GH): 89–268 ppm (5–15 dGH)

Values above are general hardness (GH). For carbonate hardness (KH), the buffer that keeps pH stable, see the water parameters guide.

Care Summary

The rubber lip pleco is a modest grey, spotted fish with a distinctive fleshy, rubbery lower lip, and unusually for the plecos on this list it is a genuine algae and aufwuchs grazer. It comes from cool, fast, highly-oxygenated Andean streams in the Orinoco and Meta drainages, which shapes its care in two useful ways: it prefers cooler water of around 20 to 25 degrees, making it a good choice for an unheated or lightly-heated tank, and it is hardy and peaceful. The trade-off is that it demands cleaner, more oxygen-rich water than many plecos and dislikes warm, stale conditions. At around 10 to 12cm it suits modest tanks, and it makes a far better small-tank algae eater than the common pleco it is often confused with. Supplement its grazing with vegetables and the occasional sinking wafer.

Tankmates

Peaceful, hardy, and compact, and an excellent algae eater for a cool or temperate community of white clouds, danios, cool-water barbs, and peppered corydoras. Because it prefers cooler, highly-oxygenated water, avoid pairing it with high-heat species such as discus. It is undemanding towards tankmates; its main needs are clean, oxygen-rich water and some algae to graze. Avoid large or aggressive cichlids.

Compatible with

• White Cloud Mountain Minnow
• Zebra Danio
• Gold Barb
• Rosy Barb
• Peppered Corydoras
• Cherry Barb

Avoid keeping with

• Large Cichlids
• Aggressive Tankmates
• Discus

Common Problems

• intolerance of warm, stale, poorly-oxygenated water
• being confused with and sold as the much larger common pleco
• running out of algae to graze without supplementary feeding
• ich if water quality slips

Sources: planetcatfish.com, seriouslyfish.com · Last updated: 2026-10-04