Bristlenose pleco

Quick facts

Adult size

13 cm

Lifespan

can live up to 12 years; captive average 5-8 years

Tank zone

bottom

Temperament

peaceful

Difficulty

beginner

Water parameters

Temperature

22–28°C

pH

6.0 to 7.8

Hardness

2 to 20 dGH

Tank requirements

Minimum volume

150 L

Minimum length

90 cm

Flow

moderate

Lighting

moderate

Substrate

any

Driftwood

preferred

Hiding spots

needed

Feeding

Diet: herbivore, feeds primarily at the bottom.

Algae wafers and fresh vegetables (zucchini, cucumber, blanched spinach) several times a week. Driftwood is required: bristlenose graze the wood biofilm and need cellulose for healthy digestion. Drop food after lights-out so the pleco can feed without daytime competition from faster fish. Despite their reputation as algae eaters, adults don't consume enough algae to replace feeding. A hungry bristlenose will rasp on plant leaves and damage them. Repashy gel food (Morning Wood, Soilent Green) is an excellent staple that sticks to surfaces and doesn't foul the water.

Vegetable matter required (algae wafers, blanched zucchini, spinach).

Nocturnal feeder; drop food after lights out so it can eat without competition.

Compatibility

• Peaceful with almost everything except other bottom-dwelling plecos. Males fight over territory and caves.
• Safe with community fish, shrimp, and snails. Ignores tankmates that don't enter its territory.
• Will attach to flat-bodied fish (discus, angelfish) and rasp their slime coat if underfed. Keep well-fed to prevent this.
• One of the best algae-eating fish for community tanks, but not a substitute for proper tank maintenance.

Habitat

Native to the Amazon and Paraguay basins. Wild-type is mottled gray-brown with distinctive bushy facial bristles on adult males (females have shorter, sparser bristles). The smaller adult size compared to the common pleco (13 cm vs 40 cm) makes it the standard "algae-eating pleco" for home aquariums. Albino, longfin, super red, and calico varieties are all commonly available. Primarily nocturnal; you may rarely see one during the day until it becomes comfortable with the tank routine. Strongly territorial toward other plecos; two males in a small tank will fight. Widely captive-bred, affordable, and available in virtually every fish store.

Breeding

Cave spawner. The male selects a cave (coconut shell, PVC pipe, ceramic tube) and cleans it, then entices a female inside. She deposits 20-100 large orange eggs on the cave ceiling and leaves. The male guards and fans the eggs until they hatch (4-10 days depending on temperature). The male does not eat during this period. Fry absorb their yolk sac over 2-3 days, then begin grazing biofilm and algae. Breeding is easy in a mature tank with caves; many hobbyists discover fry without having tried to breed them.

Common problems

Starvation is the most common problem. People assume the pleco will eat algae and never feed it directly. A bristlenose in a clean tank with no supplemental feeding will slowly waste away over months. Provide driftwood, algae wafers, and vegetables regularly. Bloating from swallowing air while eating floating foods; use sinking foods only. Bacterial infections on the bristles in males, usually from poor water quality. Ich affects them like any other fish. Bristlenose are sensitive to salt; do not use aquarium salt as a treatment in a tank with plecos.

Bioload

Bioload coefficient: 6.0 (13 cm heavy-bodied catfish; size formula gives ~8 but bristlenose are notable waste producers, so this stays close to that. hobby consensus puts them at 5-7x neon).

Bioload coefficients are calibrated against the neon tetra as the anchor (1.0). See the methodology page for the formula and how each value was derived.

Further reading

• Stocking ideas by tank size