koi died after water change- &wintertize

[Meyer Jordan]

Yup,as I said,no ammonia reading. Any reading is too high.

An ideal that is not likely to be found in any natural waterway, yet fish have survived for eons.

 

[Smaug]

Any natural water way wouldn't have any ammonia at all,even trace. If it was moving water the turn over alone would keep the very small fish load of natural water ways to nil. In a lake or well kept farm pond it's the same thing . If you have measurable ammonia in your garden pond your doing something wrong. Been keeping aquariums for years with very high stocking densitys,no ammonia reading ever.

 

[Meyer Jordan]

Any natural water way wouldn't have any ammonia at all,even trace. If it was moving water the turn over alone would keep the very small fish load of natural water ways to nil. In a lake or well kept farm pond it's the same thing . If you have measurable ammonia in your garden pond your doing something wrong. Been keeping aquariums for years with very high stocking densitys,no ammonia reading ever.

Not going to debate the natural waterway aspect here as it would take up entirely to much space in someone else's thread. Suffice it to say that Low Ammonia levels are common place in natural ponds and lakes. I might suggest a little research on your part.
Yes, zero Ammonia levels are attainable, but the issue here is when is Ammonia at a level that may cause irreversible damage to fish. Any level of un-ionized Ammonia <2% of TAN, is considered acceptable. see this calculator-
http://www.koiphen.com/forums/koicalcs.php?do=calcnh3c
and
"Free ammonia is highly toxic to aquatic life. It kills in aquariums at very low amounts. Any level above 0.02 mg/l (ppm) is considered harmful."
http://www.theaquariumwiki.com/Ammonia
As applies to the scenario presented in this thread, I state again, with the given temperature of 42F for the un-ionized Ammonia to exceed the 2% safe limit, the pH would have to be higher than 8.5 (assuming a TAN of 1.0).

 

[Mmathis]

@Meyer Jordan Regarding ammonia readings -- those of us who use a liquid test kit are relying on a visual comparison between what's colored in a test tube and a square of color on a chart. So, when I say my ammonia reading is "0 ppm," I'm looking at yellow water..... My eyes can't detect the fine variations in the "yellow" until the color is closer to the next color on the chart. And then there are the differences in ink on the color card.... If I had a more sophisticated measuring device, it would be able to tell those fine (huh? spell-check turned fine into feline, LOL!) variations. I agree with you, but just saying.....

 

[Meyer Jordan]

@Meyer Jordan Regarding ammonia readings -- those of us who use a liquid test kit are relying on a visual comparison between what's colored in a test tube and a square of color on a chart. So, when I say my ammonia reading is "0 ppm," I'm looking at yellow water..... My eyes can't detect the fine variations in the "yellow" until the color is closer to the next color on the chart. And then there are the differences in ink on the color card.... If I had a more sophisticated measuring device, it would be able to tell those fine (huh? spell-check turned fine into feline, LOL!) variations. I agree with you, but just saying.....

This is the drawback to liquid test kits. They are accurate, but because a determination of color must be made visually, the final reading is based on a judgement call of color hue. The average pondkeeper can not afford them, but photometers/colorimeters eliminate this human judgement. The color is read by a computer which in turn returns accurate results within two (2) decimal places down to levels below those detected by liquid test kits. This is why I was excited to see the new photometer offered by eXact that was mentioned in another thread. It can perform tests on 35 different parameters with a base price of $299.00. This is 1/3 of the cost of other photometers of similar ability. This is getting into the price range that is comfortable for a greater number of pondkeepers.

 

[Mmathis]

This is the drawback to liquid test kits. They are accurate, but because a determination of color must be made visually, the final reading is based on a judgement call of color hue. The average pondkeeper can not afford them, but photometers/colorimeters eliminate this human judgement. The color is read by a computer which in turn returns accurate results within two (2) decimal places down to levels below those detected by liquid test kits. This is why I was excited to see the new photometer offered by eXact that was mentioned in another thread. It can perform tests on 35 different parameters with a base price of $299.00. This is 1/3 of the cost of other photometers of similar ability. This is getting into the price range that is comfortable for a greater number of pondkeepers.

Oh goody! A new toy! Can't wait for the price to go down!