First year and failing miserably!

[Ollieman0916]

Help!! My koi are dying. This is my first year of going through a winter with my koi pond and I've lost two in the past two days. I've tested the water every few hours and everything is perfect. I'm assuming it's a temperature issue but not sure what to do about it. I live in central North Carolina and the weather has been fluctuating like crazy this past week. The water temperature was 41° on Tuesday and then our outdoor temperature is 75° today so my water temp is up to 62. I know they aren't supposed to handle such drastic changes in temperature. The pond is pretty small ~1000 gal but 3 feet deep which was recommended. That's definitely not doing enough to keep the temperatures from fluctuating so much. I can add a heater and keep the temperature warm all winter so there's less fluctuation but is there anything that I can do to help the ones that are in there now? They seem to be struggling like they are in shock- not swimming much and just hovering near the surface of the water allowing the current from the waterfall to push them around much more than normal.

It may be something other than temperature but the koi look fine and don't have any signs of disease that I can see.

Any ideas would be much appreciated!

 

[Ollieman0916]

Make that 3 dead in two days... just got home from work and found another one floating.

 

[Meyer Jordan]

Where exactly are you located?
Photos of your pond may help.
At what depth are you checking the temperature? Please post the numeric results of those parameters that you have tested.
And most importantly, how many Koi did you originally have and what sizes?

 

[Ollieman0916]

Raleigh NC
I've had the pond up and running for about 4 months with no major issues other than having to triple the filtration the first month.

I Checked the depth throughout and it's pretty consistently the same temperature plus or minus a degree. There are 2 waterfall filters that are circulating the water. There were 6 koi- 5 were 5" and one is 12"+. We purchased land and will have a much larger pond next year so I was told that this size would work for this year and then we would move them to the larger pond.

I use the test strip water kit and all the parameters were within the normal range.

If you have any other questions just let me know! I'll do anything at this point to prevent them from dying.

 

[Meyer Jordan]

Just a quick FYI---Invest in a liquid water test kit. Strips are notorious for becoming inaccurate over a short period of time especially if exposed to humid conditions.
Did you test for General Water Hardness and Alkalinity?

 

[Ollieman0916]

Good to know! I'm taking a sample of water to an aquarium supply store to have them test it now. The pH was at a 7.0-ish and the GH has always run low and I was told would run low until it was fully established which could take up to a year.

 

[Meyer Jordan]

Low GH can prove to be dangerous.
Please post the numeric values after you get the test results.

 

[Ollieman0916]

8.2 ph
PO4, NO2, NO3 all zero

He said PH is a little high but it's normally around 7.5-7.8 so he said that's not the issue. I got my koi from him and his have been outside in the same temperatures in a similar setup and the temp change hasn't effected them at all.

So confused.

he said to do a 75% water change in case there's some kind of toxin in the water but that's the only suggestion.

 

[Meyer Jordan]

He did not check Hardness (GH) of Alkalinity (KH)?
You can be confident that it is not the temperature. Large changes in temperature are only a real issue when they are relatively sudden as in minutes or a couple of hours.
A water change may induce even more stress to the remaining fish resulting in loss of those remaining. I would advise against this until more information is available.

 

[Ollieman0916]

No he didn't test GH. I tested it with my strips and it was low but it's always been low.
Another one just died.

 

[barryian]

No he didn't test GH. I tested it with my strips and it was low but it's always been low.
Another one just died.

The pond is new! I never heard ammonia or Nitrite mentioned or did I miss that as I just came in? Agree with Meyer as water temp is probably not an issue at all. The pH is fine as long as the gH & kH haven't caused dramatic changes.

 

[MitchM]

Yes, information about ammonia and water change procedure would help.

 

[Meyer Jordan]

Do you have enough test strips to begin testing you pH morning and evening for a couple of days? I suspect that you pH is fluctuating too widely.
And FYI, The generally acceptable minimum GH level is 100 or 7 dH for Koi and Goldfish. Anything below this would likely affect their osmoregulation opening them up to myriad other health issues.
Raising the GH is relatively simple and safe. All you need is Calcium Chloride (available at any swimming pool supply store) and Epson Salts.

 

[Meyer Jordan]

The pond is new! I never heard ammonia or Nitrite mentioned or did I miss that as I just came in? Agree with Meyer as water temp is probably not an issue at all. The pH is fine as long as the gH & kH haven't caused dramatic changes.

Yes, information about ammonia and water change procedure would help.

OP posted these parameter levels. Ammonia and Nitrite are Zero.

 

[MitchM]

I'm not seeing NH3 or NH4, only NO2 and NO3.