Question about Koi / goldfish eating habits

[Jay Wiener]

Question: My pond is crystal clear and plants are doing well. Looks healthy. Fish also look and act healthy. HOWEVER, in past years, they always jumped up to the top of the pond to eat when I came to feed them. Now, they pretty much stay at or near the bottom and ignore the food except for a couple of the goldfish. The koi are not coming up to feed, at least, not while I'm watching. Any ideas?

 

[Jhn]

Possibly a predator came around like a heron is the usual suspect. The fish after this occurs tend to hover, near the bottom or hide in and under things.

May want to check water parameters as well, just to be on the safe side. Especially, ph, ammonia, nitrite and nitrate

 

[Gemma]

I agree with @Jhn it could be that they're scared! Mine act that way if a predator has been visiting.
...and it's not just the Heron, or raccoon, heck I recently found out that "bull frogs" are a major threat to my koi...I knew about the snakes, but never thought a frog could be considered a predator

I have one fish in particular that gets bloody fins when stressed, that's my first clue to keep a closer eye on things

 

[Mmathis]

I agree — sound like they are reacting to a real or perceived predator.

 

[Jay Wiener]

I checked the following just now:
PH = 7
Ammonia = 0.25 PPM
Nitrite - 0
Phosphate = 3 to 4 PPM

So, the phosphate is a little high, but I don't know HOW high that is. So, I put a MUCK & SLUDGE treatment in, as prescribed in my test kit. Could that be it? How high is that Phosphate reading? Thanks!

 

[j.w]

@Jay Wiener

 

[MitchM]

It looks like there are some water quality issues.
What size is the pond, how many/what size are the fish and what are you using for filtration?

 

[Stephen Noble]

I agree with MitchM on this one. Ideally, your ammonia should be zero. Fish suddenly changing behavior especially not eating is a red flag. The O2 might be low. Also, it could be something like flukes affecting them. But my first guess is water quality.
Stephen

 

[qclabrat]

agree with potential for low oxygen. Has your fish load changed? plants? try aerating to see if they become more active. Big fish are more sensitive to oxygen issues. I lost two large GF last year which I suspect was due to oxygen problems. They just sat on the bottom, then a few days later were gone.

 

[Jay Wiener]

I have the same filter I've always had (waterfall) PLUS I added an aerator at the end of last summer. The pond and the fish appear to be healthy, though I'm keeping an eye on both the phosphate and ammonia levels which, according to what I've read, are not dangerous if not perfect. Funny thing, after doing some research, I ordered some very high quality (and expensive) koi food, which I began using exclusively two days ago. As of yesterday's later afternoon feeding, the fish have begun coming up to eat again. Who knows? Thanks to all of you for responding.

 

[Learning to Care for Koi]

I agree with @Jhn it could be that they're scared! Mine act that way if a predator has been visiting.
...and it's not just the Heron, or raccoon, heck I recently found out that "bull frogs" are a major threat to my koi...I knew about the snakes, but never thought a frog could be considered a predator

I have one fish in particular that gets bloody fins when stressed, that's my first clue to keep a closer eye on things

Bull frogs, really? I have a family of them in the pond! My fish are not eating their usual food, but they are eating something off the surface of the water, maybe water striders i am thinking.

 

[Learning to Care for Koi]

Bull frogs, really? I have a family of them in the pond! My fish are not eating their usual food, but they are eating something off the surface of the water, maybe water striders i am thinking.

The bull frogs climb on the floating plants and ride across the pond. Honestly! I took a photo today.

 

[Gemma]

I used to love seeing frogs in the pond,too, this is the first year since we built the pond, that I have a problem with them terrorizing my fish.
Years ago hubby and I saw a frog eating another frog, but I never thought to consider them a predator until one ate my butterfly koi.
If your koi are acting scared, there is a good chance that a predator is visiting your pond