Have you ever had your normally happy fish, you know, the ones that happy swim up to greet you, suddenly start hiding out at the bottom of your pond? There are a few reasons why koi hide.
What’s Bothering Your Fish In Your Colorado Pond
It can be frustrating when your koi friends seem more interested in hiding at the bottom of the pond than coming up to the surface to say hello. After all, one of the joys of having a backyard pond is watching your koi swim and interact with each other.
It can be frustrating when your koi friends seem more interested in hiding at the bottom of the pond than coming up to the surface to say hello. After all, one of the joys of having a backyard pond is watching your graceful koi swim and interact with each other.
Hide and Seek?
Koi fish have several reasons for hiding. It is a self-defense mechanism. When people are scared, they either fight or run and hide. Fish aren’t known for their fighting skills, (wah..fish ninja!) so they hide instead. By hiding, your koi fish are protecting themselves from some form of danger. But what danger?
Have there recently been new fish added to the pond?
After adding new koi fish to your ecosystem pond they’ll be a bit skittish. Koi are social creatures, and they may be trying to adjust to new koi fish in the group.
It’s like moving into a new home. You want to get all settled in before you head out to meet the neighbors. Not only are the new fish shy, but the fish that were already living there will become shy too. If this is the case, they should return to the surface soon enough.
Try giving them a little food each day. They may not come up when you are there but add a little, stand there waiting and then walk away. They will eat it eventually and will learn that you are the bringer of breakfast.
It may take a week or so to acclimate.
Water Quality Fluctuation
Water quality, pH levels, or oxygen levels changing can be the cause of your koi fish always hiding. Test the water to look for elevated pH, ammonia, nitrite, and phosphate.
If any of these levels are not where they should be, do a partial water change. Remember, when you put in 20% or more of the pond volume with new water, you have to use a dechlorinator. I would try to keep a partial water change to 25%
Recent Predator visits will completely freak fish out
If a heron, raccoon or other predator has been slinking around pond, even if they didn’t get a meal, the rest of the fish will be terrified! It may take them a few days just to act normal again. You might need to up your predator protection. When the fish feel safe they will come out more.
Read How to Keep Raccoon Away From the Pond or How to Keep Heron Out of the Pond
Stagnant Pond Water?
Low levels of oxygen can get koi feeling down. However, there it’s more likely they will be at the top of the water gasping for air than hiding at the bottom if this is the case.
Water quality includes oxygen and circulation. Fish can have health issues if they don’t have enough oxygen. Keep your pond pump running all the time, especially during hot months. It oxygenates the water and keeps it healthy. Water running through the skimmer, the filter pads, the Biofall and even running down the stream or waterfall helps clean the water.
We also use aerators too. They don’t have to be huge, you don’t have to have a pond that looks like a hot tub! Find the right size aerators for your pond and place them where there is the least amount of movement.
What if the koi are actually sick?
If your koi are stressed or sick, they’re likely to hide and not be as spry as usual. Regular cleaning and maintenance will also help prevent parasites and infections from taking hold in the first place. If the fish seem to be scraping their sides on rocks or pots over and over they might have fish lice or some parasite. Another sign is that they clamp their fins in and remain still. You might have to consult a vet!
There are a few reasons why your koi might be hiding and not coming to the surface. But with a little trial and error, you should be able to figure out what’s going on and get your koi to come out and enjoy their pond again.
