"Blanket Weed" in our pond. help!

[Hamish]

it's spreading like crazy, the boss and i spent three hours today cleaning the stuff out, and still we didnt get half of it.

we have two willow trees at the NE end of the pond, which since spring (budburst time) the algae under them has dropped down to nearly nothing (as the sunlight has) and the lillies (maybe only 70-80 plants) have taken off nicely, but no where near 70-80% of the pond is covered, maybe only 10%?

im sure in two years or so the lillies will multiply, and take alot more of the nitrate out of the water.

this is the first year for the plants in the pond, for the past 10-20 years it has just been a waterflea/bloodworm/boatmen breeding ground (hasnt been cleaned/had fish/been used as a pond so to speek).

as it comes down to it, i have a big problem with this algae.

is there anything on the market that will be okay to use to kill this stuff, that will not effect the lillies and culture's of live food in there?

i have been told buy an old farmer that they used to use copper sulphate in the troughs to kill algae, and the cattle would be fine after drinking it.

also we have some barley extract to throw into it

what about all of those algaerid/clearalgae stuff for sale?

anyone had any success with that stuff?

we just need something that somebody has used, and works (in a large pond)

any help would be appreciated!

[jn]

Hi there. Dont' use the alge killers unless you're too desperate.

Go find some PondBalance. It ties up some of the nutrients that the blanket weed thrive on so it basically slowly starves. It won't kill it but it will help stop it from thriving. Manually remove as much as you can, whenever you can though.

Pond Balance I believe you treat 1 every 10 days for 3 treatments and then monthly afterwards if required. It's a powder that you dissolve in warm water..it'snot cheap but it treats quite a fair amount of water. I have used this successfully and its safe for fish and plants. We had a terrible outbreak and it took 2 full seasons to get it under control but I think it's gone now.

Blanketweed apparently loves a higher pH. So maybe test your pH just to see. (If your pond concrete out of curiousity) Also high phosphates will do it, not necessarily nitrates.. so be very careful that you aren't overfeeding. Our pond expert (professional) recommends only every other day, once/day. He recommends Pond AlgaeFix if you really need to kill it BUT.. killing it means it will die and decompose.. making food for more algae (and stealing alot of oxygen from the water in the process)!! So unless you can kill it and vacuum, don't bother.

Oh... hang on.. you say large pond? How large?? If its really big.. get some bales of barley straw. It MUST be barley straw.. no other type. And put a bale into a shallow end of the pond so it can stay near the surface. (Or put somein a sack of something) This will take a long time to start working but as it decomposes it releases soemthing that seems to inhibit algae growth.

Tell us more about your pond

[Hamish]

Hey thanks for that, yeah we are looking for a bale of barley straw to do that.

Umm i did start a thread about the pond, but i havent got arround to putting anything about it in there yet, i should do it.. really.

its about 45-50m to walk arround (large steps, wild guess actually)

had the digger in again this morning, to flatten out a few spots arround it and slope arround some of the edges so its more plantable.

any more info about this nastey stuff would be cool@!

other ways people have treated/delt with this stuff would be cool to hear about too

Thanks again jn

[jn]

Sounds awesome Hamish!

Definitely at that size you want barley straw! You'd go broke trying to do anything else

I guess in time your plants will grow in and sort out your problem.

In another thread I mentioned rushes. I had some in a 'residential sized' pond that was way overstocked, never got cleaned and where the tenant never ran the pump. There was never so much as a inkling of algae. I had since found some references about rushes being very good at stripping nutrients from the water..maybe you could incorporate some into your plantings around the edges!

Ahh.. I'm so jealous I'm having visions of rushes and flaxes and ducks etc !!

I'm not sure if you're 'farm inclined' but whenever I see barley straw advertised in Christchurch it's usually in the Stockfeed section of the weekend classifieds.

Keep us posted

[Hamish]

ah hah! i have one of those rush plants already planted in the pond,

also as we were going arround the edges digging out the grass/weeds ther were a few young ones growing too. wasnt sure if it was a weed or a plant.

out the back of our place there is a small river/stream which has heaps of that growing.

might find a few jumping over the fence into our place. :oops:

[carla]

What on earth is "blanket weed"??? :roll:

Any proper name for it available please?

Thanks.

[Caryl]

Cladophora (I think)

It is a very long filamentous algae

[jn]

http://www.pond-doctor.co.uk/longwhatisblanketweed.html

It's evil stuff.. it grows at the speed of light! And it smothers everything and wraps itself around plants and their planting baskets and floats up in huge masses like a big seaweed infestation.

Very unsightly and a little difficult to get rid of unfortunately!

[carla]

Thanks for the link :0

And see - these common names - these are not just one plant species but many: "Blanket weed (also referred to as string-algae) is a collective term given to a number of very similar algae that both look and behave identically. The most common genera are Cladophora, Oedogonium and Spirogyra."

It so pays to identify stuff correctly to be able to do something about it. Am just thinking of the other thread about "rope fish"...

[jn]

Yeah, the trouble with this stuff is that I can't imagine the average pond keeper being able to specifically identify which type.. you'd probably need miscoscopes and stuff

The lucky thing in this case is that it seems the cure is the same regardless of which specific type it is. Plus, all the marketing for control products really do refer to blanket weed....if you turned up at a water garden place asking for a spirogyra cure they would try to send you to your GP :lol: :lol:

[Hamish]

Hey,

Thanks for the link!

And unfortunately our lab dosn't have a microscope handy, and if we did i wouldnt be able to tell the differance between the types of algae anyway.

I had asked the advice of a couple of fishkeepers and i was pointed in the direction of "blanketweed", as after visiting the local LFS the container of barley extract said "for the treatment of blanketweed etc" so i stuck with that for the description of the algae we have currently invading our pond.

If you happen to be passing Hastings sometime carla feel free to come by our place and identify the strain of algae it really is.

As you say it could help me in getting the correct treatment methods to solve this problem.

Anyway, the boss got in today (while the mercury was popping up to 40C) and cleaned a good 80% of it (again.) And yes i know in three days it will be back, but the fact that it is starting to knock it down is a kind of satisfying, and it's not building up on the top of the water making it look like a sewage pond.

Getting there!

~hamish

[carla]

You are right - it is just me, needing to have proper names so I can look it up. Most other people will be happy with "blanket weed" I suppose.

I must admit I do have 3 microscopes as well ... :roll:

[alanmin4304]

Algae needs food. No food no algae.

[Hamish]

Yeah alanmin, thats right.

but it's which food to take away. Light or Nutrients?

I dont have any fish/turtles in the pond at the moment, but there is cultures of boatmen, bloodworm, waterflea (atleast two different kinds) and cambosia (sp?), so im not keen on taking anything that will harm that away, therfore i think light, but then it ruin's the whole "scene" we are trying to create here. 60% of the pond is covered most of the day by two willow tree's on the NE side, But that is not enough.

Shadecloth? it is do-able by all means, but then we have an obstruction hanging over one side of the pond. (that isnt "natural" i guess i could say)

Nutrients? We have about 70-80 water lillies in there at the moment, and they have established themselves nicely too.

So i dont really want to remove them just to treat the water as they are starting to contribute by taking up more of the nutrients everyday they grow. (maybe i dont need to remove them for treatment?)

Now we had the digger in the far end is ALOT more plantable now, it all slopes in so its not just a straight drop into 1.2m deep.

So more lillies are a definite go ahead, its just sourcing more which is the problem! (only another 200? (ish, for now.))

[jn]

Since you don't have any fish and you have trees overhanging the pond I'd guess you have phosphates from decomposing vegetation in the bottom of the pond.

You might want to keep an eye on the trees to see if they shed into the pond (or if the leaves blow in after they've fallen). That could make things trickier in terms of maintenance and you might want to consider a net or something to help keep this to a minimum during that time of year.

But as you said, patience is the key.. your plants will take over eventually with any luck. I hope your boss is composting all that nutrient rich algae

I'd say try to plant some submerged plants too, I think lilies feed from nutrients around their roots whereas the leafy type submerged plants often get their nutrients straight out of the water column. Maybe some oxygen weed and myriophyllum and some lysmachia for a start. They should all be pretty hardy

[alanmin4304]

It is probably an imbalance between PO4 & NO3. You may be low on nitrate due to no fish. When the nitrate is increased from the urea of the fish it may come right. I suspect that is partly what happens by adding barley straw (and if so may work better with pea straw---any one know?)

[Hamish]

Overnight the pond dropped 20cm, it happened lastyear (as the rivers get dryer the aquafer (sp) drops, and our natural spring looses it's "unf") so today we had decided that when our season is over and we have a bit of time we are going to empty the pond and concrete it, water features and such.

So i have to read up on that, ive never made a concrete pond before, and i guess it isnt as easy as it seems. But there will definitly be a waterfall feature incorperated into it somewhere, not sure what else yet, maybe a platform? Will have to wait and see what we come up with.

Also will be adding a sump plug type drain to make emptying/cleaning easier.

And yeah jn the leave's do drop into the water, and they do attribute to the mass of decomposition on the bottom.

I have grabed a few different types on plant from the river/stream nextdoor, but this algae has taken over and choked it all, im sure alot has been pulled out when we have been cleaning it.

The planning starts.