Pond Boss Forums INTRO Questions & Observations Trout Summer Survival

Quick status update- as this pond is 130 miles up north in MICHIGAN from where I live. Was there Sunday / Monday - 7/24/06

Trout seem to be all alive (1 dead fish found floating near the side)

Measured D.O. on surface using chemical test kit- measured between 10-11 at 7:00am before daily feeding.

Water temp was at bottom. Feeder was OUT OF FOOD! Not sure how many days ago it ran out, cut back feeding by 20%. SO far are able to "keep 'em alive". Trying to make it through the first summer with trout.

Michael, I've been watching this post w/ great interest and as usual learning a lot from you and all those contributing.

we are just coming out of a major heat wave where highest daytime temps reached 114, and lowest night temps only to 80. I was considering trout here depending on if I could get a good producing well (supplemental water) above my pond, as they grow and survive just fine in unmanaged ponds another 1,000 feet up from me......but learning from you guys just how sensitive they are, seems like one slip and thats it. i'm thinkin it wont be realistic at my elevation, or perhaps i could do some put and take over the winter.

The best of luck to yours.

Dave:
Wow- that's some serious heat (and 53 people dead!) you are having in CA. Is that a dry heat (bad joke!) My pond is doing ok s you read, but I'm still n the learning curve for sure. Wht I didn't post int his threas is tht I stocked rainbows 3 yrs. go in the Fall (Oct.) and raised them bigger in the fall / winter / spring and ran an aerator all fall and winter long- they grew wonderfully. Used a Sweeney auto feeder and just re-filled it every 3-4 weeks. IT came to mide-June and N. Michigian temps are into mid 80's, occasional 90's and the pond tmep went to 75 and they all stressed out and died. They began swimming in circles and dozens actually went bezerk and actually jumped out and after the raccoons ate them, the bones were all that was left. I didn't know I was creating the problem by continuing to run the aerator!

The BIG deal is water temp AND O2 levels. THe min. O2 is 6mg /liter of oxygen (I know 6 is the #, but I'll have to check if that's the correct measurement scale)

My pond has been 10-11 on the oxygen measurement (pretty good) and as high as 72 in temp.

What is your pond depth, pond size, current in-flow in gallons per minute, bottom water temp and and what is living in it now? And, have you ever done a dissolved oxygen test?

Michael form Michigan

Dave:
Just picked this article on D.O. levels and fish ponds off the net. It will help to fill in knowledge gaps. And yes it is 6 mg/liter for D.O. for minimum trout survival- I checked sources

Article
Severe environmental stressors are the most frequent causes of sudden fish death in garden ponds or other fish habitats, and the lack of oxygen in the water is the number 1 stressor of all.

Two major factors contributing to fish-pond oxygen loss concern blooming algae. During daylight hours, algae make oxygen; during the night,however, the plants take oxygen. If algae are profusely blooming, the plants deplete all the pond's oxygen during the night, which in turn, causes fish inhabiting the pond to die.

Another way that algae trigger oxygen loss is by dying suddenly. Algae-bloom death occurs naturally or from chemical treatment of an algaecide. When algae die suddenly � from either cause � the oxygen becomes quickly depleted because the algae no longer are alive and making it.

Then, when dead algae begin to decompose, the decaying process even further depletes oxygen. fish have been observed gulping for oxygen at the water's surface in sixty minutes or less from the onset of sudden algae death.

In ponds stocked liberally with many fish, often the oxygen level is just adequate enough to sustain them. If any further claim on the existing oxygen is made, this delicate environmental balance will be upset. When no or inadequate aeration is provided, along with rising warm-weather water temperatures, the conditions for fish survival become critical.

As water warms, its oxygen-retaining capacity decreases. Consequently, small fountains, waterfalls, or other water-aerating devices are incapable of providing adequate oxygen for fish. Additional oxygen should be introduced through brisk aeration when fighting algae, most importantly when water temperatures surpass eighty degrees Fahrenheit.

Testing devices are the only sure method to accurately read oxygen levels. Because these devices are not usually on hand for the average person maintaining a water garden or fish pond, the easiest way to ensure sufficient oxygen levels is to provide generous and continual aeration. Pumps and diffusers that "bubble" air into the water or large waterfalls, fountains, and other "splashing" water devices are common ways to get sufficient oxygen into the pond. When the weather is warm, or if an algae problem exists, it is imperative that supplemental aeration be provided constantly, throughout the day and night.

Dave:
Add-on note to the last article post on algae, oxygen and aeration

It is NOT accurate to say areation should be provided constantly. This applies to little backyard pond where KOI are stocked, that at NOT temp sensitive. Aerating when it gets past 70, begins exposing the water to not only oxygen in the air but to the warming effects of the warmer air. After a long and difficult search, I installed a thermostat (ACF Greenhouse) that handled my 220volt airpump that turns on at 62 degrees OR less and off when it hits 65 to avoid warming the pond water.