Control The Blanket Weed Growth Cycle | Blanket Weed Cure Methods
How To Control The rapid growth of string algae
Blanket weed, a major pain the a** to many a pond keeper is especially good at colonizing fish ponds that are high in nitrates, subject to plenty of natural sunlight and poorly maintained.
Blanketweed is a generic term that is mistakenly also applied to other species of string algae (filamentous algae). This long green string like algae is easily capable of taking over your pond surface. Not only is this unsightly but it detracts from the idea of a pond in the first instance i.e. being able to see your Koi and other pond fish.
Unlike suspended algae and planktonic algae varieties its development can't be controlled by using a UV Clarifier (UV light).
It is however possible to control this green/brown nuisance that is sometimes referred to as "Pond Scum".
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what causes string algae in home ponds?
As with most things pond related a good starting point is to understand why the problem occurs in the first instance. In the case of blanket weed it is due to excess nitrates in the pond: too many fish, rotting vegetation on the pond floor, fertilizer leeching into your pond from surrounding flower beds, adding tap water to your pond (tap water contains nitrate and phosphate) etc.
Unless you can remove the level of nitrate in the pond then it will be difficult to control the blanket weed growth cycle, and this nuisance will keep re-appearing. The level of phosphates is also a contributing factor to the development of this pond pest.
The single best solution to the control of blanketweed and string algae problems is Viresco Microbial Solutions. This UK patented product is extremely effective at removing nitrates from koi pond, and controlling the blanket weed growth cycle.
You will notice that fish ponds containing lots of string and filamentous algae, tend to have clear pond water. This clear water makes it easier for sunlight to enter the pond water and therefore easier for photosynthesis to take place. Anyone with a basic understanding of plant biology will understand that all plants photosynthesize, during daylight hours, in order to grow and develop.
One other factor you will notice is that ponds suffering from excessive blanketweed (string algae) rarely suffer from green algal blooms.
Note: String algae and suspended algae are forms of plant life and like land loving and aquatic plants they photosynthesize.
Blanket weed loves summer weather because there is an abundance of the suns UV rays. The higher the levels of sunlight, the quicker blanketweed will grow.
How Do You Control Blanket Weed Growth?
As stated earlier the single best method is to remove its food source i.e. starve it to death using Viresco.
Another method of controlling string algae (blanket weed) growth is to block out sunlight. This will also prevent its development because sunlight is needed for photosynthesis to take place. You can do this by using a pergola or some other form of screen to block the sun's rays.
Some pond keepers like to add vegetable dyes to the pond water. This method is actually quite a good way to control the growth of blanketweed and string algae. The vegetable dye adds a tint of color to the pond water which in turn absorbs much of the UV light that comes into contact with the pond water. You will however have to add the vegetable dye regularly because your pond filter removes it.
Another temporary solution is to add specialized pond water additives to the pond water. These additives cause the nitrates and phosphates, present in the pond water to bind together.
Pond algaecides are commonly used to kill algae. They work by upsetting the algae's biological processes. Personally, I'm not a great fan of pond algaecide treatments; mainly due to the effect it may have on the water chemistry, and the detrimental effect to pond filter bacteria, if over dosed. Besides this is a temporary fix.
The last way of removing pond scum weeds is to use the traditional favorite; Barley Straw. When Barley Straw is added to your pond water it starts to decay (decompose), after a period of time. As it decays it releases hydrogen peroxide, which is effective at reducing algae growth.
The process of waiting for barley straw to decompose is a lengthy one, and that is why it is quicker to speed up the process by adding Barley Straw Extract.