Need lots more details; shut down how? Aeration? Pump/waterfall still working? Gallonage and number of fish + sizes? Any additives since you shut down? Need water param readings; use only liquid test kits as the strips are notoriously inaccurate. Include KH. Any runoff get into the pond? Depth of pond? Any sudden/severe temp swings in the past two weeks? Accumlation at the bottom of any organic debris? There's probably more, but that should help getting started in figuring out what may be happening.
The pond is 25x35 with a 3 foot wide plant shelf and the average depth would be about 24 inches. Shelf is 12 inches deep and the rest about 30 inches. I have 1 15 inch koi , one 8 inch koi and an unknown number of comets remaining. There had been probably 75 of them of various sizes Pulled the two 4,000gph pumps from the skimmer, these feed the stream and waterfall. I have two small 550 gph pumps on each end of the pond on the plant shelf as well as air stones to agitate the surface. There are two pond breathers also that i just plugged in earlier this week. I have had the pond for 14 years so it isn't the first time I have done this same process. I always know that i will lose a couple comets over winter but winter isn't here yet. I will test the water after work and report values. The API kit i have doesn't have KH. There are leaves that have blown in since i pulled the pumps but mother nature has given us some pretty good winds the last couple of weeks. I will work on scooping them out and tossing frogs back into the pond tomorrow when i am off of work. As far as temp swings, it is fall in Wisconsin and temp swings are what happen but nothing out of the ordinary.
on first blush, everything looks fine. I'll be interested in the water parameters. The KH measure will tell you how well you can keep the pH from crashing (this might have happened but can't see an immediate cause from everything you've said so far). I don't think you're overstocked, you have adequate water movement and aeration, aren't feeding (right?) and your fish/pond should be more or less dormant (as mine is here in Mich). Again, water parameters to see if anything is obviously amiss.
They haven't been fed in at least two months. I very seldom feed the fish, there is plenty for them to find in the pond. They usually get something when the grandkids are here. The fish have been more hanging out and not moving around which is expected behavior with the cold water. It is almost easier seeing the heron eating them rather than just this mass die off. I will have to find a kh test, mine does ph, ammonia, nitrites and phosphate.
PH is 7.5, Nitrites and phosphate are zero. Unfortunately, ammonia is .25 and I know it should be zero. I was planning on scooping the leaves that have blown in tomorrow in between work calls, (don't tell them they are paying me and i am working on my pond) but wondering if i should pump out a few inches of water and refill the pond. I have well water so i don't need to worry about treating but it would be warmer than the pond water is now. Is that something i should consider doing? It's supposed to be a tropical 37 degrees tomorrow, just perfect for dunking hands in cold water and fighting a stiff garden hose.
see my reply on the wrong response. Sometimes i am so dumb.
I assume you usually use the well water to top off, so no issues there and the water may be colder than you think, but put it in slowly and it'll alter the temp hardly at all. You've got a big pond, so more latitude.
not sure to what you're referring, snoozer; hopefully I added something of value in my above response. If not, clarify what I'm missing. And we all can make mistakes; it's what we do when we realize this that counts! We'll help you get this sorted.
PH is usually 7.5 to 8 so not much change there. I will google to see what I can use, it not a water change is easy, sort of. I have a pond vac so can vacuum and dump water as well as sucking out leaves. Running the hose, it adds back about an inch an hour.
no, it's me. I replied on one of my responses. Your help is so much appreciated.
I really wouldn't think leaves, in almost any quantity would foul the water that quickly, though maybe you have a certain type of leaf that might be toxic? Take a look around and see if any of the trees might be problematic, but if you've been doing this for years, hard to think that is an issue. Maybe there's something new? And I really lean toward maybe runoff putting some chem into your water. Had any aerial sprayings from fields nearby or neighbors? Wrong time of year, I'd think, but just thinking out loud here...
I ordered some AmQuel which binds ammonia. Still going to do a water change to hopefully by more time until it arrives. Once again, thanks for the help.
There is probably some muck on the bottom. I messed up my rotator cuff and i wasn't able to clean as completely as I should have. PT has the arm working better so i will head out and try to make things right.