Can Plecos And Goldfish Live Together? (Mistakes To Avoid)

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Both Plecos and Goldfish are common species in home aquariums. However, keeping them in the same tank raises some questions.

Can Plecos and Goldfish live together? What about their water requirements? How would they behave with each other? And what about their diet?

In this article, I’ll discuss all these questions and more, so you leave with all the information you need. Let’s get started.

Can I Keep Plecos And Goldfish Together in the Same Tank?

No, it’s not recommended to put Plecos and Goldfish in the same aquarium. Yet, with certain conditions and close monitoring, it could work.

  • Temperature Mismatch: Goldfish thrive in cooler temperatures (65-75°F or 18-24°C), while Plecos, being tropical fish, require warmer water (76-86°F or 24-30°C).
  • Dietary Differences: Plecos can sometimes suck the slime coat off Goldfish, mistaking it for algae. This behavior can harm the Goldfish and cause infections.
  • Tank Size: Plecos can grow quite large, often up to 24 inches depending on the species. This requires a larger tank, especially when combined with the space Goldfish need.
  • Aggression Levels: Some species of Plecos can be territorial, which might stress the typically peaceful Goldfish, leading to potential health issues.
  • Water Quality: Goldfish produce a significant amount of waste which can affect the water’s pH and ammonia levels. Plecos, though they help clean, can’t mitigate all of this on their own.

Also Read: Pleco Fish Tank Mates

Plecos vs. Goldfish: Behavior

The first factor worth considering is the Plecos’ and Goldfish’s natural behavior. Here is what you should know:

Pleco Fish: Behavioral Traits

Plecos come alive at night, preferring the tank’s bottom layer. They’ve earned fame for their knack to eat algae and their tank-cleaning prowess.

  • Night Owls: Plecos come to life after dark, hunting for food and checking out their space.
  • Suction Specialists: With their unique mouths, Plecos stick to surfaces to munch mainly on algae and detritus.
  • Guarding Their Spot: Plecos, particularly as they grow, can get territorial, protecting their favorite hideouts.
  • Cleanup Crew: Beyond just algae, Plecos eat leftover food and organic debris, playing a role in a tidier tank environment.

Goldfish: Behavioral Traits

Goldfish, the sociable swimmers, are active day explorers. Being omnivores, they can create a noticeable amount of waste.

  • Sunny Swimmers: Unlike the night-loving Plecos, Goldfish bustle about during daylight, roaming their tank and looking for snacks.
  • Groupies and Gentle: Goldfish enjoy company, swimming together and rarely getting aggressive, which makes them great for shared tanks.
  • Waste Generators: Goldfish are known for their waste output, prompting the need for frequent water refreshes and efficient filtration.
  • Diverse Eaters: While they nibble on plants, Goldfish also feed on insects, small crustaceans, and store-bought fish food, underlining their omnivorous appetite.

Ideal Parameters for Plecos and Goldfish

Understanding the specific water parameters required for both Plecos and Goldfish is pivotal to their health.

ParameterPlecosGoldfishBoth Types
Temperature74-80°F (23-27°C)65-75°F (18-24°C)70-75°F (21-24°C)
pH Level6.5-7.56.0-8.06.5-7.5
Water Hardness4-12 dKH5-19 dKH5-12 dKH

Pleco Fish: Ideal Parameters

Plecos, hailing from tropical environments, prefer warmer water with a slightly acidic to neutral pH. Additionally, these bottom-dwellers thrive in moderately hard water conditions.

  • Temperature: Plecos favor temperatures between 76-86°F (24-30°C), mirroring the warm tropical waters of their natural habitat.
  • pH Level: The ideal pH for Plecos ranges from 6.5 to 7.5, leaning towards a slightly acidic to neutral environment.
  • Water Hardness: For optimal health and growth, Plecos prefer water hardness levels of 4 to 15 dGH (degrees of general hardness).

Goldfish: Ideal Parameters

Goldfish are more temperate fish, requiring cooler water conditions. Their preferred pH is neutral to slightly alkaline, and they’re fairly adaptable to a range of water hardness levels.

  • Temperature: Goldfish are most comfortable in water temperatures of 65-75°F (18-24°C), which is cooler than the typical tropical tank.
  • pH Level: A pH range of 7.0 to 7.8 suits Goldfish best, indicating a neutral to mildly alkaline water condition.
  • Water Hardness: Goldfish are adaptable in this aspect, but a water hardness range of 5 to 19 dGH is considered ideal for their well-being.

Plecos vs. Goldfish: Tank Setup

A proper tank setup ensures a conducive environment, accounting for unique needs while accommodating both species.

Setup FeaturePlecosGoldfishBoth Types
Ammonia Nitrite NitrateLow levels (0ppm ideal)Low levels (0ppm ideal)Consistently low; regular monitoring
Tank SizeMinimum 30 gallons (for small species)Minimum 20 gallonsAt least 55 gallons
FoliageLikes plants & wood for hidingHardy, cold-tolerant plantsVariety with hiding spaces
DecorationsDriftwood pieces for grazingNon-sharp objectsMix of both; avoid sharp edges
FilterStrong filter (they produce a lot of waste)Moderate strengthHigh-quality, larger rated filter
HeaterRequired for consistent tempNot always necessaryAdjustable, to cater to both
SubstrateFine-grained or sandGravel or sandFine gravel or sand
PumpModerate flowGentle flowModerate with gentle zones
LightingModerateModerateModerate with shaded areas

Pleco Fish: Tank Setup

Setting up a tank for Plecos requires understanding their tropical origins and their affinity for hiding and latching onto surfaces.

A Pleco’s environment should offer warmth, stable water parameters, and ample hiding spots.

  • Ammonia Nitrite Nitrate: Like all fish, Plecos need a tank with stable and low levels of ammonia, nitrite, and nitrate. Regular water changes and a good filter are essential.
  • Tank Size: Depending on the species, Plecos can grow large. A common Pleco might require a tank of at least 55-75 gallons as an adult.
  • Foliage: Live plants offer Plecos additional food sources, though sturdy species are recommended as they might nibble or uproot delicate ones.
  • Decorations: Caves and rock formations are vital for Plecos. They provide the necessary hiding and resting spots.
  • Filter: A powerful filter is essential for Plecos, as they produce a considerable amount of waste.
  • Heater: As tropical fish, Plecos need a heater to maintain their ideal temperature range.
  • Substrate: A sandy or fine-gravel substrate is suitable, allowing for any digging behavior without damaging the Pleco’s delicate underbelly.
  • Pump: A good water circulation pump ensures even temperature and aids in oxygen distribution.
  • Lighting: Moderate lighting suits Plecos, as they’re naturally nocturnal and prefer dimmer conditions during the day.

Goldfish: Tank Setup

Goldfish, known for their graceful swimming and heavy waste production, require spacious tanks with good filtration.

Their setup should accommodate their active nature and ensure pristine water conditions.

  • Ammonia Nitrite Nitrate: Regular water testing is crucial for Goldfish due to their high waste output. Maintaining low ammonia, nitrite, and nitrate levels is key.
  • Tank Size: A single Goldfish requires a minimum of 20 gallons, with an additional 10 gallons for each subsequent Goldfish.
  • Foliage: Goldfish might munch on live plants, so choose hardy species like Anubias or Java Fern that can withstand their nibbling.
  • Decorations: Smooth-edged decorations are best, as Goldfish are active swimmers and can injure themselves on sharp objects.
  • Filter: Given their waste production, a high-capacity filter is essential for Goldfish tanks.
  • Heater: While not tropical fish, a heater can be used in colder climates to prevent drastic temperature drops.
  • Substrate: Pebbles or fine gravel work well, but ensure it’s large enough that the Goldfish can’t accidentally swallow it.
  • Pump: Adequate water circulation is crucial to distribute heat and oxygen evenly in a Goldfish tank.
  • Lighting: Goldfish appreciate well-lit tanks, mimicking their natural daylight-active behavior.

The Dietary Requirements of Plecos and Goldfish

Feeding the right diet ensures both Plecos and Goldfish receive the necessary nutrients for growth and health.

Dietary AspectPlecosGoldfishBoth Types
Food TypesAlgae wafers, veggies, occasional proteinsGoldfish pellets, veggies, occasional proteinsVariety to meet both needs; avoid overfeeding
QuantityBased on size; no leftovers after 2 hrsAmount they can eat in 2 minsMonitor & adjust for both species
Feeding ScheduleEvening (nocturnal feeding)2-3 times dailySeparate feeding times/schedules

Pleco Fish: Ideal Dietary Requirements

Despite their reputation as algae-eaters, Plecos require a diverse diet to remain healthy and active.

While algae and biofilm form a part of their intake, they also need supplemental foods for complete nutrition.

  • Food Types: Plecos benefit from a mix of vegetable-based foods and protein sources. Algae wafers, zucchini slices, and bloodworms are just some of the diverse offerings they enjoy.
  • Quantity: The amount of food depends on the Pleco’s size, but it’s essential to ensure food isn’t left uneaten for long, as this can degrade water quality.
  • Feeding Schedule: Being nocturnal, Plecos are best fed in the evening. Daily feedings, with occasional fasting days, promote healthier digestion.

Goldfish: Ideal Dietary Requirements

Goldfish are omnivorous and require a balanced diet to maintain vibrant colors and energy. 

While commercial goldfish flakes or pellets form a base, they benefit from varied additional food sources.

  • Food Types: A combination of high-quality goldfish pellets, vegetable bits (like peas or lettuce), and occasional protein treats (like brine shrimp) ensures a balanced diet.
  • Quantity: A general rule is to feed an amount they can consume within 2 minutes. Overfeeding can lead to water quality issues and health problems for the Goldfish.
  • Feeding Schedule: Goldfish have a consistent appetite. Feeding them small portions 2-3 times daily helps meet their nutritional needs without causing overeating.

Pleco Species Most Suitable for a Tank with Goldfish

Certain Pleco species can coexist more harmoniously with Goldfish than others, largely due to their temperament and size.

When choosing Plecos for a Goldfish tank, it’s crucial to select species that remain relatively small and are less aggressive.

  • Bristlenose Plecos: Reaching only about 4-6 inches in adulthood, the Bristlenose Pleco is one of the smaller species, making them more compatible with Goldfish tanks in terms of space.
  • Rubber Lip Plecos: A more compact variety, the Rubber Lip Pleco reaches around 7 inches in size and is recognized for its calm nature, minimizing potential territorial clashes.
  • Clown Plecos: Growing to about 3.5-4 inches, Clown Plecos are not only small but also have a diet that leans heavily on wood, minimizing the risk of them bothering Goldfish.
  • Temperature Flexibility: Some Plecos, like the Bristlenose, can tolerate a wider temperature range, which can align better with the cooler preferences of Goldfish.
  • Steering Clear of Larger Species: Big species like the Common Pleco, which can reach a length of 24 inches, aren’t a good fit for Goldfish tanks. Their size and potential territorial behavior as they mature can be problematic.
Clown Pleco

Which Pleco Types Are Not Suitable for Goldfish Tanks?

Goldfish are happiest in colder waters and are typically calm. Some Plecos, due to their size or tendencies, might not be a great match with Goldfish.

  • Common Plecos: These fish can become quite large, even 24 inches in length, and could inadvertently harm goldfish when foraging.
  • Sailfin Plecos: Growing up to 20 inches, they may compete with Goldfish for space, potentially affecting their serene disposition.
  • Vampire Plecos: These are tropical fish that favor warmer temperatures, which doesn’t align with Goldfish’s cooler water needs.
  • Rubbernose and Bulldog Plecos: These types might cling to slower-moving fish like Goldfish, attempting to consume their protective mucus.
  • Panaque Plecos: With a penchant for gnawing on wood, they could alter water conditions, which might affect the well-being and ease of Goldfish.

The Right Way to Add Your Pleco to a Goldfish Tank

Bringing a pleco into a goldfish environment isn’t just a matter of placing it there. It’s about a thoughtful introduction and ensuring both fish types are content.

A slow introduction and close watch can pave the way for peaceful living together.

  • Acclimation Process: Begin by letting the pleco’s bag float in the goldfish tank for about 30 minutes. This equalizes the water temperatures.
  • Water Mixing: Slowly add small amounts of the goldfish tank water to the pleco’s bag every 10 minutes over the next hour.
  • Observation Period: After introducing the pleco, watch for any signs of aggression or stress. Keep an eye out especially during the first 48 hours.
  • Quarantine: Consider keeping the pleco in a separate quarantine tank for 1-2 weeks. This helps identify any illnesses before introducing them to the main tank.
  • Environmental Enrichment: Plecos love hideouts. Ensure there are enough hiding spots in the tank, like caves or driftwood, which can reduce territorial disputes and provide comfort during the initial introduction.

Tips for Keeping Plecos with Goldfish

While it’s possible to keep Plecos with Goldfish, specific measures must be taken to ensure both species coexist harmoniously.

By addressing tank conditions, food, and behavior, one can create a peaceful environment for both.

  • Large Tank: Opt for a 55-gallon tank initially; add 10-15 gallons for each new Pleco or Goldfish to ensure ample space for both.
  • Regular Monitoring: Observe during feeding and nighttime; signs like Plecos persistently hovering around Goldfish fins can indicate issues.
  • Varied Diet: Provide Plecos algae wafers, blanched vegetables (e.g., weekly cucumber slices), and occasional proteins to satisfy their dietary needs.
  • Hiding Spots: Add multiple caves or driftwood; ensuring one hiding spot per Pleco helps in reducing territorial disputes. My recommendation: Dr. Moss Malaysian Driftwood (link to Amazon).
  • Temperature Balance: Maintain water between 70-78°F, bridging the ideal temperatures for both Plecos and Goldfish.
  • Effective Filtration: Invest in a filter rated for tanks larger than yours; this addresses the high waste output from both species effectively. I personally got the Fluval C4 Power Filter (link to Amazon).
  • Regular Maintenance: Commit to bi-weekly water changes, removing 20-25% of the tank’s water, to reduce toxin buildup and ensure fish health.

Best Tank Mates for Plecos and Goldfish

Choosing the right tank mates for Plecos and Goldfish is crucial to maintaining peace and balance in the aquarium.

While Plecos can coexist with a variety of tropical fish, Goldfish require tank mates that can thrive in cooler water temperatures.

  • Rosy Barbs: These active swimmers can handle the cooler water Goldfish prefer and won’t pester the typically passive Plecos.
  • Weather Loaches: Being bottom-dwellers, they share a similar space with Plecos but usually coexist peacefully and enjoy Goldfish’s cooler water conditions.
  • White Cloud Mountain Minnows: Small and non-aggressive, these fish thrive in cooler waters similar to Goldfish, and their upper-level swimming won’t disturb Plecos below.
  • Zebra Danios: Hardy and adaptable, Zebra Danios can tolerate cooler temperatures and tend to swim mid-to-top tank, allowing Plecos to have their bottom space.
  • Giant Danios: Bigger than their Zebra kin, these fish are energetic swimmers. They match the water conditions preferred by Goldfish and won’t disturb the Plecos.

Also Read: Can Plecos And Bettas Live Together?

Zebra Danio


For the quick readers, here’s a brief summary:

  • Housing Plecos and Goldfish in one tank usually isn’t recommended due to differences in temperature preferences, dietary needs, and possible territorial conflicts.
  • Plecos and Goldfish have distinct natural behaviors and tank requirements, making it challenging to create an ideal environment for both.
  • Careful consideration of tank size, water parameters, and proper filtration is crucial when attempting to house Plecos and Goldfish together.
  • Choosing the right Pleco species, such as Bristlenose or Rubber Lip Plecos, can improve compatibility with Goldfish in a shared tank.
  • Maintaining a harmonious coexistence between Plecos and Goldfish requires regular monitoring, varied diets, and suitable tank mates to ensure the well-being of both species.