Royal Pleco

Panaque nigrolineatus

Also known as: Royal plec, L190

Water Parameters

• Temperature: 22–30°C
• pH: 6.5–7.5
• Hardness (GH): 71–268 ppm (4–15 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 royal pleco (L190) is a magnificent, heavy-bodied fish in soft grey with fine dark pinstripes and striking red-amber eyes. Reaching around 43cm, it is a true giant that needs a tank of 400 litres or more. Its most remarkable feature is its diet: Panaque are among the very few fishes that actually eat wood, rasping and digesting it with the help of specialised gut bacteria. Bogwood is therefore not optional but essential, both as the bulk of its diet and as its preferred shelter, supplemented with vegetables, algae, and the occasional sinking wafer. It needs warm, well-oxygenated water and a mature, stable tank. Peaceful towards other species but territorial towards its own kind, it should be the only large pleco in the tank. A spectacular, long-lived, and characterful centrepiece for the keeper with the space and the driftwood to do it properly.

Tankmates

Peaceful towards other fish and a fine companion for large, robust tankmates such as peaceful cichlids, silver dollars, and large rainbowfish in a big tank. It must have plenty of bogwood, which it both eats and shelters in. Keep only one royal, as they are territorial towards their own kind and other large plecos. Avoid aggressive cichlids and fin-nippers, and remember its adult size of around 43cm when planning tankmates and tank volume.

Compatible with

• Angelfish
• Severum
• Silver Dollar
• Boeseman's Rainbowfish
• Denison Barb
• Congo Tetra

Avoid keeping with

• Aggressive Tankmates
• Common Pleco
• Fin Nippers

Common Problems

• being kept without the bogwood it must eat and hide in
• digestive problems on a diet lacking enough wood and fibre
• outgrowing undersized tanks at around 43cm
• territorial disputes with other large plecos

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