Backyard Aquaponics
A place to discuss aquaponics

Yea a copper test kit might be worth while to see if there is any able to build up in the rain water. I know lots of copper gutters are actually coated to maintain the bright copper color while others are left natrual and they oxidize. The Bright copper gutters with the clear lacquer are probably not able to leach much copper into the water.

I tested the water and ammonia, nitrite and nitrate was basically 0. The only thing wrong was the ph which was registering as 6.0 (kit doesn't go lower than that). I gradually brought the ph back up to about 6.8 using Ph-up. The water has been crystal clear as it has always been

You could find the low PH killed them Koi like a PH 7.5 ish in Koi terms a ph of 6 or lower means you have had a ph crash which is a killer for koi and i should think the comets as well.

Another of my koi died. Warning autopsy photos coming up.

I did some research and it turns out that there is a condition for Koi called being egg bound which is basically where the the Koi are unabled to spawn and basically die from having too many eggs inside them.

Certainly both Koi that have died have been overly fat and it turns out, completely filled with eggs. The last Koi (a male I believe) seems to be going ok.

It doesn't really explain the deaths of the 2 comets and baby koi but at least it seems like a plausible explanation for the deaths of the large Koi.

Autopsy Photos coming up

Iam glad to see you have got to the bottom of deaths in your big Koi,sad end for such a good looking Koi.Who would have thought she could have had that much spawn inside her and a coincidence you had two die of the same condition,lets hope all goes better from now.

Hi Spiff
I may as well add my 2 cents worth
Of all the information given the stand out for me is they all stopped feeding overnight, and then died in the perusing days, their gills, skin and organs were in good condition
That girl was very full of eggs, having 2 egg bound fish at same time sounds odd (gills look perfect), not overly mucusy skin clear eyes... all look fine so its definitely not a chronic cause leading to death
It may explain their death but I would have thought they would have shown symptoms before this (haven't dealt with Koi before) but it doesn't account for the other deaths

This sounds like some kind of acute toxicity shock, as in something added/happening to the system causing a sudden result
Could be due to poison spray
Town water being over dosed???
Dead short causing an electric shock?
It was new years recently, did you have flashing sparkling fireworks that scared the death out of your heavily pregnat fish?

Sorry that's all I got, I hope you get to the bottom of it
Cheers
Bazzwaldo