Beginning and experienced pond owners suffer the same problem in blanket weed growth. Blanket weed or string algae is prevalent, even in those perfectly built ponds, fountains, and lakes. Untreated blanket weed accumulation in water can plague, and, worst, kill ponds or lakes. Blanket weed grows mostly on marginal plants, but it sometimes grows at the bottom of the pond. They multiply so fast that may leave you off guard to where they suddenly pop up.

Overfeeding Fish Can Make Blanket Weed Grow Crazy in Your Ponds
While most farmers are looking forward to summer, koi keepers are reacting differently as spring approaches. Why? Summer is the most favourable season for blanket weed to germinate and cause trouble in your ponds and lakes. Blanket weed grows quickly as it receives enough sunlight and nutrients from fish. Blanket weed is also known as filamentous algae and lives in koi ponds. There are varieties of koi pond weeds or filamentous algae such as Cladophera, Rhizoclonium, Vaucheria and Ulothrix.

A lot of pond owners are not aware that overfeeding fish can exacerbate the water balance and foster the growth of blanket weed. The excess feeds contain nutrients such as nitrates and dissolved ammonia – the important nutrient source for blanket weed. Blanket weed can easily grow in water with high pH and phosphates. There are two kinds of algae growth: green water and blanket weed. Blanket weed does not grow in green water, but if there’s clear water, the blanket weed can grow and keep the green water away.
Removing Blanket Weed – A Big Problem
Blanket weeds cling to rocks, plants, and pond’s surface, making them difficult to remove. Blanket weeds are unsightly, but they don’t pose direct threat to ponds’ health. In fact, blanket weed provides nursery for newly hatched koi fry.

However, blanket weed should not cover the entire pond for it is can also affect kois. Like what has been discussed earlier, blanket weed develops quickly and its growth is really appalling. Blanket weed can be controlled in different ways. So how can you control the blanket weed from infesting your pond?

The best way to control or remove the blanket weeds is by reducing the factors that contribute to their growth. Sunlight, nutrients, and warm temperature fuel the formation of blanket weed. If the pond receives excessive sunlight, you may use pergola to block off the sunlight and prevent blanket weed photosynthesis. Pouring vegetable dyes in the pond water is a long-term treatment that gives the water a shade from the sun’s rays.

One the pond has been cleared, you have to remove the dead algae from the bottom to prevent the nutrients from re-entering the cycle. Adding aquatic plants like water lilies, lotus, or hyacinths can minimize the sun light that penetrates in the water. Reducing the amount of phosphate and nitrate in water is proved to be beneficial. Using the natural means of eliminating blanket weed help achieve the right balance, and does not harm the water itself. Otherwise, treating blanket weed problem with algicides or weed killers poses drawbacks. Weed killer routinely kills blanket weed, making those algae become immune to chemicals.