Can Plecos Live in Outdoor Ponds? (Cold Water & Plecos)

Help Spread Pond Keeping Knowledge!

Can Plecostomus Live In Cold Water Ponds? (Guide to Pond Plecos)

Plecos come in all shapes and sizes; ranging from tiny aquarium species to much larger pond dwellers.

Plecostomus are a subfamily of tropical bottom-dwelling sucker catfish native to South America that can grow up to two feet and will eat a very wide variety of foods, including vegetables, dead fish, algae (as discussed in a previous article, one pleco is capable of eating all of the string algae per 1,000 gallons of water), and mosquito larvae. They belong to the family Loricariidae, and are also known as armored catfish. There are more than 150 species within this family, meaning there’s quite a range of sizes, temperature tolerances, and temperaments.

One of the smallest pleco species, the white spotted dwarf (hypancistrus) pleco, reaches a maximum adult size of about 2.4 inches, while one of the largest pleco species, the adonis pleco, has been known to grow over a meter (39 inches) in size. Plecos in general grow quickly, and depending upon the species can grow up to a foot per year (even the smaller dwarf varieties will double or triple their size in just a few months to a year).

Overall, most plecos seem to get along just fine with other fish species but prefer to be the only one of their kind, so try to ensure that each pleco has adequate space (1,000 gallons of water per fish for larger varieties such as the common pleco, and at least 100 gallons per fish for smaller varieties like sailfin plecos). Some of the most commonly chosen pleco species for ponds and aquariums include the:

Can Plecos Survive Cold Water? Are There Cold Water Plecos?

A Common Pleco. Photo by Raphaël Covain, available under a Creative Commons Attribution-Share Alike 4.0 International license.

As discussed above, plecos are a tropical species hailing originally from the freshwater streams and rivers of South America (specifically the Amazon River Basin), and as such are generally better suited to more mild waters. If kept outdoors, plecos do best in tropical to semi-tropical regions. They do just fine in temperature regions as well provided they are not left outside over the winter. Most plecos are tolerant of waters ranging from 65 to 85 degrees Fahrenheit (18-30°C), though they prefer temperatures between about 75 and 82°F (24-28°C). With that being said, there are some pleco species that are hardier than others, and may be able to withstand some cooler waters.


A Bristlenose Pleco. Photo by JanRehschuh, available under a Creative Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0).

The common pleco is considered one of the most resilient, favoring temperatures ranging from 72 to 86°F (22 to 30°C) but able to withstand temperatures into the mid to low 60’s (15°C~) provided it’s not for an extensive period of time. Much below this, and they may start to develop health issues, become lethargic, may float up to the surface, and could die if low temperatures persist. Bristlenose plecos, despite their small adult size of only 3 to 5 inches, are a bit more cold resistant, able to survive water temperatures that fall into the 50’s (10°C~). Some have found sailfin plecos to be able to withstand similar temperature minimums as bristlenose plecos. Overall, plecos should not be left to overwinter outdoors if you don’t live in a warm region. To help plecos survive winters, you could utilize a pond heater or bring them inside to an indoor pond or aquarium, provided it’s large enough to house this hefty species. You will also need to be sure to not stress the fish when capturing it to move it, as this make them much more susceptible to illness and disease, and also makes it more difficult for them to adjust to any temperature differences in the water when you move them to a new container.

Considerations When Keeping Plecos In Garden Ponds

1) How Big do Plecos Grow? (Some, Quite Big!)

Depending on the species, plecos can grow really large, so you’d need to make sure your pond can accommodate them.

Before purchasing any plecos for your pond, there are a number of factors that should be taken into consideration. First off is their size, depending upon the species. As mentioned previously, some species can reach several feet in length while others may only be a couple of inches. For the larger plecos, you’ll need to make sure that your pond is large enough to accommodate them; for smaller plecos, you’ll need to be sure to place them with other fish that won’t eat them. You will also need to have an indoor space large enough to keep them during the winter if you live in a region where temperatures drop much below 60 degrees Fahrenheit.

2) Is Your Water Quality Good Enough?

Plecos naturally inhabit areas of high water-flow, so waterfalls and fountains can help add aeration to the pond.

Plecos are well known for their ability to consume large quantities of algae. However, they also generate a fair amount of waste, often more than they consume. This means having to clean your filters, pumps, and overall pond more frequently. It’s recommended to vacuum your pond and change 25 to 50% of the water on a weekly basis if you have plecos.

Since their natural habitat consists of freshwater rivers and streams, plecos do best in an environment that has plenty of aeration and water movement. Incorporating a small waterfall into your pond or simply using a high powered filter should both oxygenate the water and increase the current enough to suit plecos just fine. This may not, however, suit other fish species that prefer still waters, so you’ll have to do some research to figure out compatible fish species. They get along well with most other fish (except for their own kind), so the trick will be just trying to match up some basic habitat requirements. This includes a pH of 6.5 to 8, and a water hardness of 5 to 19° dH.

3) Do You Have Hiding Spots?

As bottom feeders, plecos like to lounge about at the bottom of water bodies, munching on algae and anything else they come across. They need hiding places as well as things to anchor themselves to; most pleco species really enjoy having wood in their pond or aquarium. They can anchor themselves to it, use it for hiding, obtain some nutrients from it, and the wood will also act to help keep the pH within the range that plecos survive best in.

4 ) Are You Choosing the Right Pleco?

You should also research different species, as they can differ widely in size and appearance. For example, snowball plecos are all black (or very dark), but covered in white spots that give them a polka dotted appearance. The golden nugget pleco is similarly dark, but covered in yellow-gold spots, with its fins and tail tipped beautifully in the same color. Sailfin plecos have, predictably, a very large dorsal fin and can range in patterning from spots to squiggly stripes to an almost camouflage pattern.

Overall, you should make quite certain that you’re aware of all of the requirements of a pleco, as well as the size that the particular species you have will reach. Many people get rid of plecos once they reach adulthood, releasing them into the wild as they become too large for the pond or too large to overwinter indoors without purchasing a more sizable container for them. However, unless one lives in South America, this is quite a bad thing to do, as plecos are an invasive species outside of South America. They are able to completely alter the trophic dynamic of an ecosystem as well as the nutrients available to native species, as they consume algae and out-compete other fish species, and are not highly predated on by other animals. They also generate a great deal of waste, thereby disrupting the water quality and existing ecological balance that native species in that area have adapted to and depend upon for survival.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.