Blanket Weed – What is it?
Blanket Weed (Spirogyra adnate) is one of the most prolific aquatic weeds found in ponds in the U.K. In The USA it is called Long String Algae which aptly describes its thin stringy look. It is not a plant but a filamentous algae and it’s presence in a pond is not only unsightly but blocks light from the water and even makes it difficult for fish to swim in the pond. There are also other similar aquatic weeds which are filamentous algae and the most prevalent of these are Cladophera, Rhizoclonium, Vaucheria and Ulothrix (Ulothrix is a Chlorphyte like Spirogyra and looks very similar).
Blanket Weed can start to grow at any time of the year. It is most likey to start by a spore being brought to the pond by a Heron or other water bird which it has picked up on it’s feet from another pond.
Left on its own the weed will eventually take over the whole pond or lake. Removal by hand should only be undertaken as a last resort as moving the weed causes spores to dislodge and drop to the bottom of the pond and start the infection all over again.
Pondsludge – An explanation
Dark, smelly sludge is found in slow moving and static water at the bottom of ponds and lakes. It comes from the organic waste from fish excrement and dead leaves, seeds, flora and fauna that drop into the pond, sink to the bottom and becomes a thick brown sediment. The nutrients in it can promote the creation of unwelcome and harmful bacteria which then reduces reduce water quality and the oxygen levels which it turn affects and can kill both plants and aquatic creatures. It can also make the water look cloudy and unpleasant. It also produces noxious gases such as H2S (Hydrogen Sulphide) which give the smell of rotten eggs.
