Algae overgrowth

Algae growth is a fact of life that every aquarium owner will face sooner or later. Some algae growth is normal and healthy, but excess algae growth is unsightly and can be hazardous to fish and plants.

Like any plant life, algae thrive on three basic necessities: water, sunlight and nutrients. If an excess of any are available, algae will grow like wildfire, just like weeds growing in a garden.

What causes algae overgrowth?

Obviously you can’t do without water in your aquarium, but you can control the amount of light and nutrients are in the water. Here are the common reasons for algae overgrowth.

These are the most common algae that grow in our aquariums:

Blue-green algae

They are dark green to blue-black and cover plants and decorative objects with a slimy, foul-smelling film.

String algae

These are cotton-like threads which infect the entire aquarium, starting at the leafstalks.


If black-green spots appear on the leaves of the aquarium plants, diatoms have taken up residence in the water tank.

Beard algae

The brown-black beard algae are very difficult to remove as they form long filaments on the leaf edges or stalks as well as on wooden edges.

Brush algae

The dark green to black algae either float around in the aquarium or settle on stones
and plants.

Green algae

Their light green to green filaments and cotton-like threads are normally an indicator for good water quality. However, they also compete with the aquarium plants for nutrients.


Call into your local store today to discuss your pet’s personal needs with our Maxi Zoo Pet Experts