Anyone know how to get rid of a pond algae bloom?

[sawtooth]

For some reason this has happen really fast but not sure how to deal with it. Some kind of chemical I guess?

 

[wingn]

For some reason this has happen really fast but not sure how to deal with it. Some kind of chemical I guess?

A bale of barley straw in the pond often does the trick

 

[EddieWalker]

it's happening because your water is full of nutrients that the algae is eating. Fertilizing pastures can cause this by enriching the water when it's washed down to the pond during a storm. But also plants deteriorating in the pond can provide those nutrients. There are a lot of chemicals out there to kill the algae, but there is usually a second bloom after the chemicals break down. There are some fish that will eat the algae, but they are not very effective on bigger bodies of water. Same with UV light. In my opinion, just letting it bloom until it eats itself out of food, and it will disappear on it's own. You just have to stop feeding it. Figuring out what is being added to the pond that the algae feeds off of should be your first step.

 

[RickB]

Aeration and or chemicals. Mitigating underlying causes.

 

[KennyG]

Various things will work. For a smaller pond, barley does work. However, for long term pond health, aeration is the best answer.

 

[radios1]

chlorine works great if you don't have fish in it that you want to save.. there are fish friendly algae killers made too..

 

[wingn]

Various things will work. For a smaller pond, barley does work. However, for long term pond health, aeration is the best answer.

Barley straw is cheap and doesn’t upset the general balance of the pond. I’ve found it a quick and effective solution to a sudden bloom. In my case it was blue green algae which is poisonous to stock and so I needed a quick fix. I have not had a repeat in ponds I have treated.

 

[sawtooth]

Ok great points. So my pond is about 1 acre in size or just under. How much barley straw is needed you think?

I believe what’s happening is there have been a couple leaks in the pond that caused it to drain down about 10 years before we bought property. Then 2 years ago during heavy rains somehow the lower leak sealed up raising the pond about 5-6ft thus killing some of the vegetation and trees that were about 10-20ft tall. These materials are decaying now which maybe the root cause. The dam has large trees growing on the back side which I’m sure is the cause of the leaks. We still have the upper leak but to be honest the pond is almost too deep so it’s probably better anyway. It’s basically a deep valley that was dammed up around 1930-40. On dam end it’s about 20ft now. If the upper leak stopped would go to about 30’.

 

[wingn]

Ok great points. So my pond is about 1 acre in size or just under. How much barley straw is needed you think?

I believe what’s happening is there have been a couple leaks in the pond that caused it to drain down about 10 years before we bought property. Then 2 years ago during heavy rains somehow the lower leak sealed up raising the pond about 5-6ft thus killing some of the vegetation and trees that were about 10-20ft tall. These materials are decaying now which maybe the root cause. The dam has large trees growing on the back side which I’m sure is the cause of the leaks. We still have the upper leak but to be honest the pond is almost too deep so it’s probably better anyway. It’s basically a deep valley that was dammed up around 1930-40. On dam end it’s about 20ft now. If the upper leak stopped would go to about 30’.

I put in one or two whole bales. So they don’t ‘wash up’ on the shore I tie them to a weight (piece of iron/ rock) and put them out into the pond.

 

[John_Mc]

Chemical can kill algae, but the treatment never lasts. It's treating the symptom, rather than the cause. Eventually, the chemicals wear out or break down. If you have not removed the cause, the algae will just grow back.

First thing is reduce the source of nutrients flowing into the pond (fertilizers, manure washing down from further up in the watershed, leaves/trees/grass clipping getting into the pond.) All of that is food for the algae.

Next is aeration. We use an electric aerator in our pond. Our neighbors have a windmill driven one. The so-called aerators that are sprinklers or fountains in the middle of a pond are just about completely ineffective for all but the shallowest of ponds - they only aerate the surface. You need to aerate the whole water column. That takes a diffuser at the bottom of the pond (more than one, if you have a large pond) fed by a compressor. Both my and my neighbors aerators are made by Koenders. Mine is electric, my neighbor's is windmill-driven. They work well, and last a long time.

Add dye to darken the water in your pond. This reduces how far sunlight penetrates into the pond. Algae needs sunlight to grow. Less sunlight penetrating into the pond means less algae. There are two colors commonly used: black or blue (I use a mix of both). It's basically highly concentrated food coloring. I buy mine from Clean-Flo.

Add beneficial bacteria to the pond. Various types of bacteria can help break down the muck at the bottom, and can out-compete the algae for the nutrients in the pond (basically starving the algae). I use Clean-Flo as my source for that as well, but there are others. I generally dose the pond once a month during the summer and get very good results.

Both Koenders and Clean-Flo are great about talking customers through what they might need. Give them a call, and they'll walk you through the options.

A pond is never going to be a swimming pool. However, with the steps above, kids are swimming in our pond any time it's warm enough out.

For more information, check out Tim Matson's books on Earth Ponds. He has written several books, has a website with some information, and does consulting on pond construction and dealing with pond problems. Just Google "Tim Matson Earth Ponds" to find him.