Best way to kill algae in fish pond?

[Firefighter912]

Pond is possibly .5 acre or so. Has brim and other fish in it.

It is covered with green algae. Pond is getting low due to drought.

Any good way to kill the algae and not the fish?

Thanks

 

[RNeumann]

When I built Koi ponds I would use a grayish green powder that killed the algae but didn’t harm the fish. I have no clue what it was- I got it in a ziplock bag. This article may point you in the right direction.
Algae in Koi Ponds & Water Gardens

 

[oosik]

You know why your pond is choked with algae, don't you? From somewhere there are nutrients running into the pond. Before you get all H++L bent on killing the algae - stop the nutrient inflow into the pond. Forget about the nutrients - forget about stopping the algae growth.

The gray/green powder/granules the RNeumann is talking about - Malachite Green. It's the most common product used to kill algae in aquaria.

Be careful if you use Malachite - there is a VERY DEFINITE relationship between - oxygen concentration/pH/temperature/amount of Malachite used.

 

[vlcakc]

Stopping nutrient inflow into a pond will mitigate the algae problem, but is often impossible to accomplish. The watershed for my pond is composed primarily of agricultural fields that are routinely treated with ag fertilizers. There is absolutely no way to stop the inflow of nutrients. I have successfully treated filmatous algae with Cutrine-Plus in the past. A hard rain with an large influx of fresh water was also very beneficial. Vic

 

[KennyG]

Chemicals can kill the algae but I don't think it's the best solution. I added an air pump and completely eliminated my algae problems. My pond is supplied by farm runoff and completely loses flow over the dam for a month or more in the summer. Before the aeration system it would get completely covered by algae. Now only a trace at the edges.

 

[ning]

Chemicals can kill the algae but I don't think it's the best solution. I added an air pump and completely eliminated my algae problems. My pond is supplied by farm runoff and completely loses flow over the dam for a month or more in the summer. Before the aeration system it would get completely covered by algae. Now only a trace at the edges.

What aeration system did you use?
This is on my to-do list this spring but I haven't pulled the trigger on a DIY or commercial system yet...

 

[KennyG]

Bought the pump and diffuser on Ebay. Can't remember the brand's and I am away from home now. Lots of internet information available.

 

[murphy1244]

See this link for pond stuff Lake & Pond Management Specialists | Lake & Pond Supplies & Service – Jones Fish Hatcheries

I also use a 2 diffuser air pump.

 

[radios1]

I have a pond with an EPDM liner, and a good aeration system. the only thing that gets in there is fish food, air, and sunlight. I think it's the sunlight that is allowing the algae to grow.. airborne algae, that is..

 

[vlcakc]

Chemicals can kill the algae but I don't think it's the best solution. I added an air pump and completely eliminated my algae problems. My pond is supplied by farm runoff and completely loses flow over the dam for a month or more in the summer. Before the aeration system it would get completely covered by algae. Now only a trace at the edges.

If you have a smaller pond and nearby electric service to power the pump, controlling algae with aeration is a very good choice. I considered aeration as an option before using the chemicals. Multiple aeration units would have been required due to pond size and the nearest power source was over a quarter mile away. I don't have a boat on the pond for maintenance access and I don't share the paranoia about "chemicals" that some people seem to, so the choice was obvious. Vic