We are new pond owners. We bought a house with a koi pond and added 4 koi that we bought at the pet store. There are also 3-4 small goldfish in the pond with them. (We bought the goldfish first.) We’ve had two of the koi for 3 weeks and the other 2 for a month. We bought them from the same store. They seem healthy in appearance and when we see them come out from hiding they swim normally. We have a pond that is close to 200 gallons. We thought they were used to an aquarium and needed more places to hide. They had a cave and an elevated slab of rock to hide under as well as some lettuce plant when we added them. We added more hiding places and plants. I have tested the water weekly. It appears to be perfect. We also added some Japanese trapdoor snails.
Will they ever come out and allow us to enjoy them? They don’t even come out when I feed them. At least not right away.
Welcome to GPF!
There's a few things to talk about, but we can start with your query. There's a few reasons they hide, but the most obvious is that a predator has been around. As long as this keeps happening, they'll hide for survival. You can set up a trail cam and see if this is happening, probably early morning or dusk when you're not as aware, though herons in particular are very patient hunters and hunt most of the day and early night.
Now, if not that, then yes, eventually with some small feedings and as they see the goldfish come up for food, they will join in. I'm assuming you've had no issue with the goldfish being visible?
The second and more important note here is this; koi grow to an average of 26" and easily can be over 36" when full grown, in a 2-3 year span. The general rule of thumb here is ONE THOUSAND gallons for ONE koi. And 250-500 gallons for each additional one. So you're in for problems almost before you start. Koi exude an extreme amount of waste, esp as they grow, and grow they will. For the sake of the fish, it would be much better to keep ONLY goldfish in such a small pond. There are many who post here that suddenly have water issues and fish dying and it's mainly because they can't understand this process. A large pond is much much easier to try keeping koi but a small one is doomed for failure, or at best, you'll have fish that are too large and can't move in a container of water you'll have to filter in ways you can't yet conceive (if you want to even atttempt to keep them alive, not to mention the goldfish).
As you're doing, more floating plants will make them more comfortable; fish like when they know they have some cover. Too, a shallow pond makes them feel more exposed as well, and I'm pretty sure your preform (I'm assuming) is not more than 18" deep at its deepest point.
It's a hard lesson to learn, for both new ponder and especially the fish and we try to help both thrive.
