Pond Boss Forums GENERAL QUESTIONS Water chemistry DO/Temp Chart?

I am wondering if anyone knows of an accurate source for a chart that has the preferred and then fatal DO/Temp variables for different fish species?

I don't know of a chart, though there could well be one. Dr. Dave Willis knows this stuff, maybe he will chime in.

CJ and Dwight -- I'm guessing there is not an accurate chart because multiple variables are involved. For example, low DO may not kill fish if methane and hydrogen sulfide are low in one water, and the same DO may result in a kill in another water with more of those toxic gases. The duration of the bad conditions can also have an effect. So, I'm sure this is not a satisfying answer ( ), but it is the reason that no one has a simple chart.

I can say that fish tolerate lower DO values in the winter, at least for a while, than people commonly believe. LMB, BLG, and walleye are ok down to at least 2 ppm. They may not eat or move much, but they are surviving. As it drops below that, they may start to go, but not necessarily right away. I'm sure both of you know that partial kills are common, even within the same fish species. If conditions are tough for too long, then we can actually get some deaths after the ice is gone and the water starts to warm. Often, the sum total of the stress they encountered over the winter has apparently weakened them enough that common bacteria can kill some of the fish. Once weakened by the bacterial infection, they usually develop the fungal infection on the surface of their bodies that gives them that milky appearance.

Tougher fishes such as northern pike and yellow perch are definitely ok down to 1 ppm, and probably even lower. Again, they tend not to bite much, sometimes there is a quick sunset flurry of activity and not much else all day, etc. Fathead minnows are the champs -- if there still is 0.1 ppm, they are merrily surviving.

NOTE
Cody says - DAVE GREAT ANSWER

Dave, That was a great explanation! A chart that would include all the variables may be a "Life's Work" for someone.

Yeah, throw in a computer program where you can plug in the variables and I am sold! HAHA

My programming specialist said he could write that program. Cost to you would be about $12,500.00, plus a $1250.00 per month maintenance. We would be happy fly out to your location and provide training with all expenses on your dime.

CJ/Dwight -- did you see that?? A nod of approval from Bill Cody! You can't get a better stamp of approval unless it is Sir Bob Lusk himself.

Thanks for watching and checking, Bill.

Wow Bill is using those mod skills to add and edit notes. That may be a first.

When I hit the lottery it'll be my first purchase!

CJBS2003, I have a pdf entitled "Water Quality Chart" which I can email to you. PM me for my email address. It shows upper & lower thresholds for most freshwater sportfish, koi, tropicals and bait minnows. Categories include DO, temp, pH, CO2, ammonia, nitrite ... etc. These may not be specific thresholds which induce immediate death, but they do represent points where fish begin to stress and are more susceptible to disease, as Dr. Willis pointed out. Generally speaking (in warm water), a DO of 3 is low. A DO2 is bad and DO1 is REALLY bad. If you are seeing DO values of 3 or less in your pond at any point in the day, I would recommend you look into some type of aeration system.

Haplo Man,

Thanks, I'll send you that PM... Welcome to the forum as well. The chart isn't for anything specific. Just general knowledge...

Haplo, welcome to the Forum. Would you mind posting that pdf or is it proprietary?