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Can Koi Fish Get Sunburned?

Can Koi Fish Get Sunburned?

Asked By: Shane of Chillicothe, OH

Sunshine has its benefits, but it can also be harmful in excess. Direct sunlight with no shade can raise the water temperature in your pond and reduce the oxygen available to your fish. All those rays can also fuel algae blooms and give your fish a sunburn (yes, really!)

As it turns out, koi fish in backyard ponds and water gardens are particularly susceptible to sunburn. Combine a shallow body of water with no shade, and in long hours of hot summer sun, koi can get sunburned rather easily.

Prevent Sunburn With Koi Pond Shade

Like all other fish, koi rely on a natural protective layer known as a "slime coat" that fends off everything from disease to injury. When koi fish are exposed to too much direct sunlight, their slime coats are compromised, and sickness and lethargy follow quickly. Left unresolved, long-term exposure to sunlight will cause a koi's untimely demise. Fortunately, it's a simple problem to fix, and we have the right supplies to help.

  • Terrestrial Shade: Trees and Marginal Plants growing alongside your pond can provide plenty of shade from the outside. For example, blue flag iris and dwarf cattail cast cool, shady shadows for your fish.

  • Floating Plants: Floating aquatic plants, like Water Lilies and Water Hyacinth, create ample underwater shade for your finned pals. Plant lilies in containers and place them in strategic spots around your pond, or add a few water hyacinths to create a floating hideout.

  • Get Creative With Canopies: If planting trees or plants isn't an option, consider installing a tent or canopy over part of your pond. In addition to creating protection from the sunshine, a canopy adds dramatic flair to your backyard décor. The Pond Guy PondShelter cover net provides shade while keeping your water garden free from leaves and debris.

  • Fish Shelters: For a super easy solution, drop some fish shelters, like the Nycon Koi Kastle Fish Shelter, in your water garden. Another option is to build fish caves with carefully positioned rocks to create a shady shelter that protects fish from the sun and lurking predators.

  • Protective Pond Dye: Pond dye adds an attractive tint to your water garden while also shielding your fish from harmful UV rays. The Pond Guy PondShade is available in natural Blue Sapphire and dramatic Black Pearl in easy-to-dose liquid formulas to mix the perfect color.

A word of advice: Don't over-shade your pond. You want to maintain an area with some sunlight to bring out koi colors, keep the water temperature comfortable, and boost plant growth.

If your fish show signs of heat stress, check your water temperature with a submersible thermometer and perform a partial water change if the water temperatures exceed the high 70s. You might also want to add supplemental water treatments to boost fish health. Pond Salt promotes gill function and reduces fish stress, and Stress Reducer Plus alleviates stress, restores slime coats, and removes dangerous toxins from the water.

More Koi Pond Shade Ideas

Do you want help designing the perfect sun shelter for your koi pond? Contact us for expert advice from our pond professionals at 866-POND-HELP today!

Read more about koi pond shade and shelters below:

Why Fish Hide
Dye in a Water Garden?
Importance of Plants in a Water Garden
How to Create Fish Habitats in Large Ponds

Last Updated: May 9, 2024