Hornwort covered with string algae


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After fertilizing my water lilies with what I now know was not the best fertilizer (too high in phosphorus) I had an explosion of blobby, stringy algae in the pond. It comes off most of the plants easily when disturbed and I scoop it out when it floats on the water, but the hornwort is totally covered and it does not come off. The hornwort is brown and does not seem to be doing too well, it is so encased it just looks like giant algae blobs, and the fish eat algae elsewhere in the pond but they don't clean off the hornwort. How can I remove the algae from it to save it? If I try to manually pull it off, it just seems to shred the hornwort and pull off its leaves. Is it worth removing the hornwort from the pond and putting it in a bucket to treat the algae, then returning it, and if so what's a good method to de-algaefy the hornwort without hurting it?
 
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addy1

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Is this the first summer with the hornwort? With mine it took around a year plus a bit to get really growing. Mine looked horrible and fell apart now it is a jungle.
 
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As I said in another thread about string algae it kills plants. I lost almost all of mine this year. The only suggestion I can offer is to pull the plant out of the pond and put it in a bucket containing some hydrogen peroxide or better yet sodium percarbonate. I don't think the chemicals will kill your hornwort but can't guarantee it. I waited too long to take care of mine.
 
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Yes, it's the first summer. The hornwort seems to have a lot more string algae than the other plants to the point of being engulfed, hence my concern for its survival. I'll try the hydrogen peroxide, thanks. I don't have any sodium percarbonate: is that the same as washing soda?
 
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Yes, it's the first summer. The hornwort seems to have a lot more string algae than the other plants to the point of being engulfed, hence my concern for its survival. I'll try the hydrogen peroxide, thanks. I don't have any sodium percarbonate: is that the same as washing soda?
 
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No it's the same as Oxy Clean but I'm not sure if Oxy Clean adds something else, you can use it for cleaning purposes. I get mine off of eBay. I would give Oxy Clean a try (or Oxi Magic made by Clorox). Only use a small amount, maybe a teaspoon in a bucket of water and put the hornwort in. What do you have to lose?
 
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I tried the hydrogen peroxide since I had some and it worked quite well to clean up the hornwort. I put it in a bucket, picked off as much of the algae and other debris as I could by hand, then sprayed with hydrogen peroxide, let it sit a while, and rinsed with clean water, then repeated. It seemed to work well (though time consuming) and most of the algae was gone after multiple sprays and rinses. The hornwort was looking a lot greener once I finished and returned it to the pond. But now, within a couple days it looks completely brown and dead again even though now it's not covered with algae anymore. I am puzzled.
 
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You may have overdosed the H2O2 - maybe should have just done a quick rinse and then rinsed with water. But who knows. I can't grow hornwort for the life of me!
 
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In my experience hornwort can be picky but once it's "happy" it will take off and grow like crazy.

Does your pond get much sunlight? Do you have fish in the pond? Is your pond temperature very warm?
 
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It gets a lot of sunlight. There are a few goldfish in the pond who don't seem to interact with the hornwort at all, and I don't think it's that warm, but I don't know what temperature it likes. The other plants in the pond are doing okay, except a bit of elodea I have which is also doing poorly. There is a shade area in the pond but that's not where the hornwort is. I tried putting some there in the past to see if it helped but it didn't seem any happier there. It's always been brown even before it got covered with slime, and some I bought that started bright green ended up turning brown. Actually the first time I've seen it look green in quite a while is after I finished the peroxide treatment. It got really green when I did that. But after a few days it is back to brown and bits of it are flaking off. I know it's not supposed to like being moved, but I don't understand the green/brown issue.
 

addy1

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I would let it just sit and see how it does next summer. Mine appeared to "all die" after I put it in the pond the next year it came back and has been growing great ever since. It is in full sun.
 
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The hornwort started disintegrating into lots of little bits, so I scooped it out and put it in a bucket for now. I will try to sort through and return any apparently living pieces to the pond once it finishes this process.
 
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Fertilising a pond can be risky, hornwort seems to be an indicator of something being 'off'

All you can do is wait for the excess fertility to be mopped up and hornwort tries to bounce back

Salvaging remnants to fresher water in a shady place would provide a stash to replenish the recovered pond in a few months
 

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This is my hornwort after it has been in the pond for around 4ish years. I do nothing for it, sometimes I do yank and toss.

It started out bad, falling apart, figured it was not going to grow well...................fooled me!

The depth here is around 5-5.5 feet. The fish love to hang out in it.
20190715_102853.jpg
 
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I had a similar experience with hornwort I purchased this year for my new pond. It turned brown and died off so I removed it. My pond was still in the green water stage. Recently the water cleared and there growing in the deep part of the pond was a host of hornwort entwined around the stalks of the lily pads. I was sure it was all gone.
 

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I have it growing in other ponds now, not a forest like the big pond. But my pond water is perfect, no green water, no cloudiness, zero string algae this year even in the small ponds.
 
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This is my hornwort after it has been in the pond for around 4ish years. I do nothing for it, sometimes I do yank and toss.

It started out bad, falling apart, figured it was not going to grow well...................fooled me!

The depth here is around 5-5.5 feet. The fish love to hang out in it.View attachment 122804
Wow! So cool, iI wish mine would grow like that! It is struggling with the string algae too.
 

addy1

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Give it time, it might just do well.

I don't get string algae, to many plants that suck excess nutrients out of the pond for it to grow.
 
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I have tons of plants on the edge, creeping jenny, watercress, ivy, mint, calla lily, dwarf palm, mexican petunia, one little water lily, ect. And a floating island too. All are doing fantastic, but my hornwort wont grow, and my water hyacinth all turned black and died!
 
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