Strange koi behavior?

[pletlibo]

Hey guys,

I just joined this forum to ask this question about my koi. I've had my garden pond for a few years, and enjoy changing my edging/equipment and fountains regularly. And last winter, unfortunately, I had fish death in my pond so this year I had to buy some new fish. I picked up 3 new koi from a local store a few weeks ago. When I first put the fish in, they swam to the bottom and weren't active. This isn't strange behavior for fish you've just added to the pond, and I've experienced it before. But then, weeks went by and nothing changed. I haven't seen my koi actively swimming around nearly at all. But then one time when I was doing a water change after draining some of the pond to install new equipment, it was like a switch flipped and the fish started swimming around actively like crazy. But just as soon as this active swimming started, it stopped and they went back into hiding. Then, about a week later I did the same thing and the same thing happened. Does anyone have an explanation as to why my fish are only active when I change water (and probably shock them)? I haven't seen them eat since I added them into the pond. Does anyone have any explanation/remedy for this behavior? I'm worried they'll starve.

Thanks!
Nicholas

 

[Lisak1]

Welcome @pletlibo !

A bit more information about your pond would be helpful. How many gallons is it? How many fish total? What kind and what size? What kind of filtration? And out of sheer curiosity - what kind of equipment do you change so often that requires water changes?

One thought that I had - sometimes odd things or sudden changes will bring on spawning behavior, for example heavy rain or adding new fish. Could it be spawning? Are you familiar with what it looks like when fish spawn?

 

[pletlibo]

Sure thing!

My pond is right around 1,000 gallons. The three fish exhibiting the strange behavior are the only fish in the pond. It's a "garden pond" that I use for water gardening and keeping fish. As for filtration, I use a large standard canister power filter that has sponges and bio balls. The piece of equipment I was installing was the skimmer, and I needed to drain the water level so that the sealant could cure correctly.

I'm not familiar with spawning behavior, but there has been heavy rain. I can't imagine that it's spawning behavior though because these are the only fish in the pond, and this behavior started right as I added them into the pond and I still can't get them to swim around!

One thing that may be worth noting, is that due to the heavy rains the water has been pretty muddy recently. The way I designed the edging around the pond left the water vulnerable to heavy rains washing in mud and muddying up the water. I've been addressing this problem by pulling the liner up above the level of ground around the pond. This seems to be fixing the muddy water but it's still clearing up.

Another thing to mention is that there isn't very much water movement, as my pump only moves about 1,000 gph and I don't have alternate aeration. Lack of aeration causing them to retreat to the bottom of the pond has crossed my mind, and I'm looking into aerators and also just today bought a new pump that pumps 3,100 gph to increase water flow and aeration to the pond (as well as to make my fountain look a little nicer!).

Again, any insight would be appreciated.

 

[j.w]

@pletlibo could be the fish are just still spooked by anything that comes near them or any changes you make. Might just take them quite awhile to get familiar w/their surroundings as they feel more comfortable.
If you have a lot of extra liner left around the edges perhaps you could make a step down a few inches all around the pond by lifting up liner and digging out dirt. Set some rocks on that shelf below the water on the liner and build up the top edge under the liner w/dirt or rocks and put more rocks on the edge above the lower rocks that are in the water. This way you can't even see the liner anymore around the edge in the water and the berm you make too above that will help keep the runoff out.

 

[JamieB]

I’d say they are still spooked. Any chance you’ve got critters in the yard that want to eat them? Like raccoons at night? Stray cats? And if they’ve lived their whole lives one way, like glass tanks, suddenly the pond is a big scary place.

 

[DonnaD]

I received 2 koi for Mother’s Day, yesterday I saw one for the first time, the other is still in hiding, I think they just have to adjust to new surroundings.