all fish in my pond dead!

[justbugged]

An alga bloom would explain the lack of oxygen. With the heat this is the most likely explanation. Take a water sample to the nearest Aquatic store and have them test it. Nitrate or Nitrites would do it to. Or freeze some of the water and buy a test kit. Get a good one. They don't all test for Nitrates and Nitrites. See what happens and let us know please.

 

[Akane]

It depends what type and size of pond we are talking about here. A pond with a pump or filter is quite a different matter for your typical farm pond. It's standard if you live in an area with farms to have ponds dug in the livestock pasture. Completely common to have the livestock drinking out of them with no issues. Low oxygen is possible for a variety of reasons but the treatment again depends on the type of pond. For most ponds on a farm it's not practical if not impossible to install anything that would cause surface agitation and they are never cleaned for organic matter. Just adding depth can help if the problem is over stocking or low water levels in dry weather. It won't help if the cause is algae blooms from fertilizer run off in the fields which is more likely if your weather has been rainy instead of dry. The water (well or city) from farming communities can be a real pain in an aquarium from all the fertilizer run off and resulting phosphorous levels that make algae go nuts. That situation would be completely harmless to livestock. It generally only results in green forms of algae or occasionally brown which are not dangerous. Blue green algae isn't always toxic either. It's a fairly common occurance in certain aquarium setups and only kills the fish maybe 1 out every 50 times. If any of those were the problem I would not be concerned about livestock drinking the water. Other chemical run off though would concern me. Things that are designed to be toxic to plants or critters in the fields could be bad if the livestock were drinking it. Although most of the time it would probably be too diluted to cause harm.

It will take more investigation and consideration for the exact setup of the pond to determine what caused the deaths and what can be done about it if anything.

 

[patandchickens]

Quote:
I dunno, IME it is not uncommon to have solar- or wind-powered agitators in farm ponds. Yeah, you do have to haul them out, or go out there in a rowboat, occasionally if they plug up, but evidently people manage to do it.

Blue green algae isn't always toxic either. It's a fairly common occurance in certain aquarium setups and only kills the fish maybe 1 out every 50 times.

Pretty much ANY sunny pond will have some degree of seasonal bluegreen algae blooms, and yes they are usually harmless especially when minor, but in general when fish start dying it is smarter to keep stock on a different water source if at all possible. Even if the fish were initially killed more for reasons of temperature or anoxia (as that can *cause* a problematic bluegreen bloom). It is not necessarily something you can eyeball, either. See sources such as those found by

http://www.google.ca/search?hl=en&s...tnG=Google+Search&aq=f&aqi=&aql=&oq=&gs_rfai=

Pat​