Posted on

what causes blanket weed to grow

What causes blanket weed to grow

This is a question that pond owners will probably be asking forever and unfortunately the news isn’t good, because when you have clear and healthy water, the chances are high that you’ll get blanket weed. This is after all a natural, native, filamentous algae, the spores of which can be brought to your pond by insects or birds or even by the wind. Don’t fight it – accept it but we can tell you how to manage it so well that you wouldn’t even know it was there.

Subscribe to our emails!

Another available option is to choose an algaecide. This will only ever be a temporary solution, however, as you are killing the growth but not dealing with the root of the problem. Technically, an algaecide is simple and easy to use – always follow the instructions and ensure that it is totally suitable for your pond and all of the creatures or wildlife therein. Speak to staff at your local Maidenhead Aquatics store if you are in any doubt over which product to use. This is the perfect option for those with fish-free water features or designer ponds where regular treatments can be easily administered without worrying about the knock-on effect to any pond inhabitants. As with any garden chemicals, the use of these aquatic ‘weedkillers’ should be seen as a temporary solution and shouldn’t be relied upon, as it does little to tackle anything but the symptoms of a more complex problem.

Don’t miss out!

Lastly, we come to the “magic” option. Rather than removing, or killing, the blanket weed directly, you can remove the source of the growth. Phosphate is a key asset in the onward march of blanket weed, so if you can remove or reduce this chemical cad, you can win the war with the weed. There are many different products on the market designed to do this, but we would recommend Stop Blanketweed by Evolution Aqua. It is easy to use, safe for all wildlife and extremely effective in binding phosphate in your pond and usually, just one treatment is all you need. Directing your attack on the true source of the blanket weed problem is always the best way forward and is suitable for any and all pond owners.

What causes blanket weed to grow

Nitrate is the last stage of the nitrogen cycle, the biological process that happens in any aquatic system (whether it be a pond or aquarium). Nitrate is considered relatively safe to your pond in lower doses, and in a perfect world, we would carry out small water changes every month with nitrate free water, and keep the nitrate level diluted and under control. The problem is that nowadays nitrate can often be found in high levels in tap water (one of the results of fertilisers applied to crops in fields which then get into our water system). Depending on where you live, water changes using tap water are therefore not as effective as we would like.

For any plant to grow, they require three factors – water, light and food.

What makes up the algae’s food?

Good maintenance is also helpful in controlling algae. The less waste and silt there is at the bottom of the pond, the less there is to break down through the nitrogen cycle and end up as nitrate. We recommend maintaining your pond at least 10 times a year, ensuring the filters are kept clean, the pond vacuumed, and water changed (obviously refilling with as low nitrate water as possible). Also ensure the quantity of fish does not get too many for your pond! Goldfish can breed very well in garden ponds, and as a result if they are very successful you end up with too many fish for the pond, meaning you will add a lot more food resulting in higher levels of phosphate leaching into the water.

Planting Basket Soil in your pond is a first source of phosphate, as it contains low amounts of phosphate. The actual quantity can be quite variable, and garden compost (sometimes recommended in garden books) can have quite high quantities within it. This phosphate will leach out of the soil over time straight into the pond water. ACTION – Using a good quality aquatic soil, (or just gravel if the plants you are growing are low in requirements for nutrient) helps to reducing the availability of phosphate from this source.

Why does blanketweed grow so prolifically?

Food for the plants is in the form of nutrients. Many different elements make up these nutrients, but the two we concentrate on are nitrate and phosphate. These are both measurable by a standard pond test kit set and controlling them always reduces algae growth.

What causes blanket weed to grow

It has three main causes, excessive sunlight, a high pH and excess nutrients. Nutrients in pond water, caused by the build-up of organic matter, act as a food source for the blanket weed. While sunlight stimulates growth through the process of photosynthesis. Blanket weed, like other forms of algae, thrives in ponds that have a higher pH, typically anything above 8.5. These three factors are also the likely reason for any recurring problem.

Typically, it appears either floating on top of or submerged within pond water as clumps of thick green, hair-like strands. These dense clumps have no leaves or stems but will attach themselves to pond walls.

What causes blanket weed?

Available in: 300g & 1KG.

Pond owners often attempt to remove string algae with a pond net or by hand. However, this method alone is not advisable. Moving/pulling it while it’s alive releases spores into the pond water, that will cause more to grow in the future. To remove it from your pond, you will first need to kill it.

Not sure if you have blanket weed?

Ornamental ponds with high sunlight exposure and organic nutrients create the perfect environment for it to thrive.