Help the development of the site, sharing the article with friends!

Algae have already spoiled the desire of many aquarists for their passion. Once the microorganisms have formed, they multiply like sand by the sea. Swift action is now required. After all, the unwelcome aquatic plants indicate an unbalanced ecosystem. The aquarium not only suffers visually, some types of algae even have a negative effect on the health of the fish. Now it is time to remove the algae. Fortunately, there are also a variety of biologically sound alternatives. The best thing is that the home remedies are usually already available in every ordinary household.


Algae in the aquarium can only be removed effectively and in the long term if the cause of their formation is known. Only with the knowledge of the exact trigger is it possible to find the right home remedy. The most common causes include:

  • dead plant remains
  • stagnant water
  • droppings or undetected fish carcasses
  • too high a phosphate content in the water

notice: An aquarium is a small biotope. Every living being contributes to a functioning symbiosis. An excess of algae indicates an imbalance in this tiny habitat.

Different types of algae

In order to successfully combat aquatic plants, in addition to analyzing the cause, it is also helpful to identify the exact algae species. Here is a brief overview of the most common types and their properties:

blue-green algae

  • actually not algae, but bacteria
  • recognizable by the bluish-green film over the aquarium's furnishing elements
  • damage the filter system
  • very stubborn
  • indicate that the nitrate level is too high
  • Control measures: dark location, replace half of the water for three days, predators (snails, sucker catfish)

green algae

  • highly developed algae species
  • shows up as green dots on discs and young plants
  • occur when there is an excess of nutrients
  • Control measures: predators (honeycomb catfish, blue catfish, Siamese algae mullet)

thread algae

  • subspecies of green algae
  • occur when there is too much light and nutrients
  • rapid spread
  • attack aquarium plantings at the roots, causing them to die off
  • Control measures: Amano shrimp

red algae

  • thrive in strong water movement (good nutrient supply)
  • occur with low CO₂ content
  • Control measure: Increase CO₂ content

brush algae

  • subspecies of red algae
  • grow in corners and edges of the aquarium
  • prefer strong currents
  • the most unwelcome type of algae due to the massive spread
  • dark green to black color
  • occur when there are too many nutrients and too little CO₂
  • Control measures: remove infested plants, predators (blackfin fish, barbel, guppy), vacuum off gravel, reduce current

beard algae

  • subspecies of red algae
  • recognizable by small hairs
  • very stubborn
  • cover furnishing elements and filter systems
  • arise from either a nutrient deficiency or excess


  • Brownish coating on stones, plants and other furnishing elements, oxygen bubbles
  • occur when there is a lack of light and an excessively high carbonate content
  • Control measures: nutrient withdrawal through feeding competition (fast-growing plants, Pispelmouths), vacuum gravel, exchange a third of the water for softer water

notice: The trade offers a large number of chemical agents for removing the various types of algae. Although the use of fungicides promises a very high success rate, the use of toxic substances is not recommended. As I said, an aquarium is an ecosystem that fungicides would destroy. In addition, these funds only help in the short term. Long-term disposal using natural substances is then definitely the better choice.

Remove algae: home remedies

It doesn't take a lot of money to remove algae. Even small interventions, changes and home remedies can help to eliminate them in the long term and even prevent algae formation. Some methods are somewhat controversial, but others have proven to be very effective. Of course, the suitability of a home remedy always depends on the fish population, the space available and the type of algae present.

Design of the aquarium

With the right setup of an aquarium, it is possible to take action against certain aquatic plants. Each water basin should be equipped with a filter. However, its performance depends on the size of the aquarium and the number of fish living in it. Two filter systems are ideal, with one sucking up coarse dirt such as faeces and another filter cleaning the water from fine dirt particles.
The floor covering also plays an important role. For example, blue-green algae prefer light-colored pebbles. Replacing them with dark stones drives away the unwelcome plants in no time.

Create the right lighting conditions

Not only the conditions inside the aquarium are decisive for the formation of algae, but also external influences. In particular, the supply of light determines plant growth. Plants need light to carry out photosynthesis. In doing so, they release nutrients into the water. If there is too much light, a excess of nutrients, but if it is too dark, the content is not sufficient. Various types of algae benefit from this imbalance.

create balance

The ratio of aquarium size, fish population and furnishing elements should always be precisely measured. Lots of fish produce lots of poo. Here is once again referred to a correspondingly powerful filter. The amount of food should also be adjusted to the number of aquarium inhabitants. If there is leftover food, it serves as food for the algae. In addition, certain fish species have the function of natural predators. So that they also feed on the algae, it is advisable to give a reduced amount of food so that the fish do not eat their fill completely.

plant aquarium

Plants are a direct competitor for algae growth. Both living things need nutrients to thrive. Fast-growing aquarium plants thus deprive unwanted rivals of the necessary nutrients. They also regulate the CO₂ content of the water through photosynthesis. Diverse planting is advisable. A monoculture would do the opposite.
An important focus is also on fertilization. Choosing the wrong fertilizer quickly leads to an oversupply of nutrients. However, deficient nutrients should be supplied in a targeted manner. An exact water analysis is therefore highly recommended.


Straw is a popular, simple household remedy for removing blue-green algae and the like. Although it is primarily used in garden ponds, it is also effective in removing unwanted plants in a water basin.

  • dried barley or wheat straw are suitable
  • For every liter of water there are four to five handfuls of straw
  • sink the straw in a sealed plastic bag in the water basin
  • Poke small air holes in the plastic with a toothpick
  • after about two days the algae population should recede
  • Change straw and plastic bag every ten days

notice: Mistakenly, money is still considered an effective method to combat algae infestation in the aquarium. However, this is strongly discouraged, as the copper is poisonous to the fish.


The best way to prevent algae from forming in the first place is to prevent them from forming. Any aspects that promote algae growth should be ruled out in advance. The choice of location is the top priority for prevention. An aquarium must not be too sunny, but also not too dark. The light supply should not be less than ten hours and not more than twelve hours. Anyone who cannot ensure the minimum level of brightness naturally can use artificial lighting. On top of that, it is important to constantly check the water quality. Test strips are available from specialist retailers for this purpose, among other things to determine the nutrient concentration.

Help the development of the site, sharing the article with friends!