Why add a chemical without trying a natural method first?

I can't remember if it is barley straw or oat straw, but a few bales in your pond should help the algae situation.

Maybe someone else can say which one works... Or, you could do a Google search using keywords like "pond algae straw".

Did you ask this question on the GW Pond forum?

I dont like putting anything in pond that shouldnt be.I have areator on mine that helps,I also have a pair of mute swans that get rid of algae.I very seldom have algae problem.

Barley straw took care of the algae in my small pond. I don't know how much you'd need in one as large as yours, but you might do some research into it.

Johanna

you could put in some algae eating carp they work wonders! and wont bother the other fish.

We had some pond "experts" tend our pond 20 years ago, they used copper sulfate. It took 10 years to get the pond balanced. I would never do it again, I float a bale of alafala on it. The bale gets pretty ripe by the end of summer. I put flower seeds on it it wes pretty floating around.

If you put grass carp in your pond, be sure to buy sterile ones, as they are invasive and can tear up a pond.

A pond full of floating algae, that is to say "green water", means that the pond has nutrients, usually nitrogen, that is going un-used by the desirable plants.

In other words you need more water lillys or "underwater oxygenator plants" to use up the nutrients. Make sure your lawn fertilizer isn't leaching into the pond.

I think the barley straw bales work as a home for billions of micro-organisms that also use up the nutrients.

Copper Sulphate is generally safe, although copper is quite toxic to sheep, so don't use it if you have any sheep that will drink the treated water. Copper is less toxic to cattle, but above a certain concentration it is still toxic.

I have often heard of submerging straw bales in the water to control algae and that it is quite successful. You would probably want to at least a half a dozen small bales around the pond, depending on how deep it is.

Also, reduce the nutrient loading of the pond as suggested to cut down on the food supply. If your pond is quite shallow, lots of algae might just be something you can't prevent, but then it would be expected to be invaded by reeds, cat tails, or water lillies, too.

I have a 3/4 acre pond and have grass carp in it. I bought them over 3 years ago and they are great at keeping the weeds and algae down.

In NY you have to get a license to get the grass carp, since they want to make sure you are purchasing the sterile grass carp from approved sellers.

It was an easy thing to do.

Do you put plant tabs or fertilizer in it? Algae grows if there is a lot of phosphorus in the water from fertilizer. You need more plants growing in the water, not the soil, to absorb the nutrients. Iris, grasses and reeds, free root, will help a lot. Just put a rock on them to hold them down and let them grow free root in the water.

Also, you will get an algae bloom every year in the spring. It's natural and will settle down in a healthy pond, in a month or so when the plants start growing vigorously.

You can always use a pump and run it through an out-of-pond filter in a barrel then back into the pond. Use very small filter material, like quilt batting, and clean it often.

My sis uses this stuff called aqua shade. It makes the water bluer and the algae can't grow in it as well. You need to put it in early in the spring before you get much algae and don't exceed the amount it says to use. Don't use it when the weather is hot because when the algae dies off, it takes the oxygen out of the water.They water their horses out of the pond and haven't had any problems. Horses sure seem more delicate than cattle, so I'd expect they'd be ok.

Most algae is self limiting. There are no studies that show that barley straw actually works, Lots of high strength H2O2 will work, or something like duckweed that grows quickly can lock the nutrients up and then you can drag the plants out and dump them on your soil as fertilizer.

Copper Sulfate works at killing algae but just adds to the nutrient load in the pond as the algae decomposes. Trout, Koi are some species that are negatively impacted by copper based products. Barley Straw has been known to work, but you need flow and oxygen for it to be effective. Pond Dyes work great at reducing algae by limiting sunlight and photosynthesis. You may want to add beneficial bacteria to help to balance the nutrient load. The bacteria will compete with the algae and plants for the nutrients in the pond.

Here is a link that might be useful: Cool link for bacteria and pond dye product

We have a shallow 3/4 acre pond on the farm that use to get full of algae during the summer. We dug a 60 foot long 8 foot wide 2 foot deep trench on the side that has a slight upgrade giving a total drop of 6 foot to the pond water level at the top side of the ditch.

To create good water circulation within the pond installed a 2 inch PVC pipe line from the far end of the pond to the top end of the ditch. To pump pond water to the top of the trench we used an underwater style pump within a triple filter cage. Partially filled the trench with Michigan peat moss and planted cattails the full length and width.

It is the cleanest water and you can see a quarter in 6 foot of water now. The cattails will filter and use the excess nutrients and contaminates form the water keeping it very clean. One could drink from it with no fear. Nature always has the best way to do things!

Nature is installing submersible pumps now? :)

What you've just described is called a bog filter (in case people want to look it up). There is some ecological concern about peat mining but like the duckweed locking up the nutrients is the best answer. Since the water is not acidic like a bog (turns out the bog filter is nothing like a real bog) the peat will be exposed to slow decay processes, Coconut coir will last a big longer, incorporating a healthy dose of horticultural charcoal can also help stabilize the filter bed and increase the cation uptake capacity of the filter soil. As with the duckweed the system will perform better if the vegetation is harvested rather than rotting back into the filter bed. Just cut the young shoots and peel them, then steam them and eat like asparagus. Irises are also a solid choice for this area, and they can spread rather rapidly.

My friend chris has a pond and he put that crap in their and it didn't get rid of it, killed ALL his fish, and killed ANY animals that drank out of it.

Grass carp,sterile or otherwise, do NOT eat algae. Rather they can harm your pond in all kinds of ways. They will eat any aquatic plants that are there. If no plants are there to absorb the nutrients, they will be freed up to feed even more algae blooms. Also, grass carp churn up the bottom in their search for food, keeping nutrients stirred up, again benefitting algae blooms. Grass carp grow large and will take up much of the biological bass in your pond that might otherwise be occupied by other aquatic life. I repeat: Grass carp do NOT eat algae. They will eat all kinds of aquatic plants and even graze on shoreline grasses if the water level allows it. But they do not eat algae. Many waters in this country have been damaged by pond owners and lakefront property owners who buy and release grass carp.

Here is a link that might be useful: www.activistangler.com

We put an aerator in our pond. It took 3 years to catch up with the back log of biomass but for the last two years we have had a healthy looking (and smelling) pond with only light algae, and duckweed on the edges. Copper sulfate is one of those poisons that have to be used in just the right amounts. Too little, and nothing happens. To much and everything dies, and not enough middle ground.

Biofilters are good. You don't really need peat moss for them. If the cattails are happy in your local mud, use that.

The water doesn't have to circulate very fast (although it's pretty...) If you run your pond through the filter once a week, it's lots. A 1 acre pond, 8 feet deep has about 2 million gallons in it. A week has half a million seconds. 4 g/s = 240 gal/min. 240 g/min needs a 3 inch line. Also -- it doesn't need much drop. Just enough to move the water out of the way. 2 inches is enough. The lower the head, the less power you need. 240g/min = 2000 pounds per minute. Lifting that 2 inches takes 300 foot pounds per minute. Or about 1/100 HP ignoring friction.

Cattails on the edge of the pond help a lot too. The wind then does your circulation. Cattails can make it a lot harder for a todler to get in the pond my mistake too, especially if you have edges that are shallow enough for a wide band of them.

I can see a lot of different ideas where I can apply in my garden pond. I always want to maintain my pond very well and I should look for a lot of great ways in doing it.

Here is a link that might be useful: Barley Pond Straw