Tuesday, July 10, 2007

Blanket Weed under the Microscope

Personally I use a concentrated liquid form of Barley Straw Extract at the beginning of the year to try and combat the worst of the blanket weed (although this liquid form can be expensive).

Barley straw is a more natural method of combating the blasted weed, but even at the start of the year before the various enzymes and bacteria start doing their work blanket weed can build up quite quickly in the pond.

In a stream you tend to get it all year long, simply because the water is shallow, and the sunlight has the most impact, therefore it has to be removed by hand regularly.

Like so many people, in the past I tried using chemical based products and solutions to treat blanket weed, but the main trouble with these is they just breakdown the structure of the blanket weed making it slippery and slimey and even more difficult to remove from the pond.

I prefer to let the weed grow to a suitable length, then use a cane stick to dip into the water and "twizzle" it in the blanket weed which quite easily attaches itself and wraps around the cane.

I just keep twizzling to "wind" in all the weed, which eventually breaks off leaving only short lengths attached to the pond sides and bottom.

After a bit of twizzling I then use a sharp Stanley knife to cut the blanket weed away from the cane. A twizzled lump of blanket weed is really very tough stuff and won't easily pull off the cane.

This cane method just isn't possible if you use chemicals to break down blanket weed.

Another alternative which I use is my pond hoover, but generally I use that to clean excess sediment, leaves etc from the bottom of the pond.

After physically removing as much as possible, I then give another good dose of barley straw.
After this first major growth in the spring, the pond balance and enzymes seem to get the upper hand and the blanket weed is much less of a problem for the remainder of the year.

Since building my DIY bio-filter I have never had a problem with green water.

Yes, blanket weed sometimes at the start of the year, but never green water all year long.

If this is your first year with a new pond, do not be surprised if you get a couple of green water blooms a couple of weeks or months apart as the pond and bio-filter all establish their equilibrium. Large pond plants are good additions but they need time to grow and then they will use excess nitrates (essentially fertiliser) produced by the bacteria life cycle in your pond, so starving phytoplankton of nitrates (they are the little blighters who actually make the water go green).

Did you know that phytoplankton is generally always there in your pond during the summer? It is simply "photosynthesis" caused by sunlight which makes them turn green, and when they multiply in their thousands and millions because of too much nitrate (think fertiliser), this is what causes your pond water to become green pea soup.

During daylight these microscopic plant-cum-animals absorb carbon dioxide and give out oxygen - good for your fish - but at night the reverse happens, and they take in oxygen, and give out carbon dioxide. This is when your fish can suffocate if you have a really bad green water problem!!!

Now to finish off you really should marvel at the beauty and mechanics of these tiny creatures.

Picture copyright © Wim van Egmond - www.micropolitan.org

Take a look at the Microscopy UK's wonderful "Smallest Page on the Net"
You will find some amazing micro-photography and learn a lot about what algae really is.

Absolutely fascinating!

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At 24/3/08 2:07 pm, Anonymous Anonymous said...

Wow! I loved this spot on blanket weed. And the microspcopic picture is really cool.

I'd like to throw in a comment on algae prevention...In case your're not already doing it, always keep a good amount of plants in your pond. If you've got fish, the plants will compete with algae by consuming the nutrients fish 'wastes'.

floating plants such as water hyacinth and water lettuce are particularly good at this!


At 21/4/08 10:23 pm, Blogger Jim Prior said...

Spot on. You're absolutely right, but there are many things which go towards keeping balance in the pond.
Plants are a very essential element. Feeding too much is another thing people overlook too often.

At 23/4/08 3:08 pm, Anonymous Anonymous said...

Hi Jim,
Came across your blog whilst looking for advice regarding our fish- wonder if you could help?
Two of our fish have been moving very little, are loosing their colouring but most of all have bad swelling to their undersides.
One of them has swelling to its right eye and both of them are now just floating and not able to move. One of them is however moving its eyes and mouth.
Do you know what this could be or have any advice?
Thank you,

At 24/4/08 7:25 am, Blogger Jim Prior said...

Hi James,
Its sounds very much like your fish are suffering from Dropsy. The symptoms you describe are classic.
Have a read of my article here....
Good luck, I hope you've caught it in time.

At 30/5/08 4:05 pm, Blogger Backyard Gardener said...

I've always used a UV clarifier to control algae. Going forward, what cost savings can I achieve by using barley straw extract instead of a UV clarifier?

At 30/5/08 6:35 pm, Blogger Jim Prior said...

GMan, normally you use a UV clarifier to address green-water problems, i.e. water-borne algae. My blog post refers to the use of barley straw additives to combat Blanket Weed. And the main thrust of my web site is the use of natural balance achieved by bio-filters, non-excessive feeding, aquatic plants, and reduction of sunlight, regular addition of natural bacteria, etc to combat green water. UV clarifiers are useful in extreme cases or as a quick fix to green water problems, but be careful that the ammonia, nitrite and nitrate levels are not unduly high, as UV clarifiers can mask the root problem. It may produce CLEAR water quickly, but do you have CLEAN water!?


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