Species of Algae

Make sure you read this page before going onto this page (except if you’re into the hobby).


Blue Green Algae

Blue green algae appears as slime in the gravel

Blue green algae is actually a cynobacteria. It often appears as slime in a black, blue, or green color. Low nitrates can cause cynobacteria. Also, substrate with a lot of fish waste sometimes could cause cynobacteria. It often grows in substrate but sometimes can grow on decorations. To get rid of it, the h202 treatment works, overdosing, excel works, or blackouts. Water changes are a big help and should be used with one of the treatments.



Green Dust Algae

Green dust algae invaded glass

Green dust algae usually appears as a green dust looking algae on the glass. It usually grows when lighting is too much or if fertilizers are dosed too high. The reason why you don’t scrape it right when you see it is because the algae can float when ejected from the glass then goes back onto it. To get rid of it, wait 3-4 weeks until it is fully gown. Then, scrape all the algae off and do a water change. This way, the algae gets off and gets taken out. Sometimes you’ll have to do the treatment twice




Staghorn Algae

Staghorn algae growing on plant

Staghorn usually appears as tiny hairs when small and grow to be a antler looking algae. It can appear as a black, brown, grey, and white color. It usually grows on plants but sometimes grows on decorations. Too much lighting, too much fertilizers, disturbing substrate with lots of fish waste without a water change, disturbing dirty filter, not enough water flow, or low co2 and cause staghorn algae. To fix it, raising co2 levels will help. If you don’t want to buy pressurized co2, raising your light fixture can help. Cleaning the filter and substrate (water changes) can help too. The h202 treatment or overdosing excel helps too.




Brown algae

Brown algae invaded aquarium

Brown algae or diatoms usually grows on glass, decorations, and sometimes substrate. It usually has a dirty brown color to it. It’s natural for it to grow in a newly set up aquarium. Scraping it off the glass helps. After a while of having your aquarium, it naturally goes away.




Green Water

Green water is often caused by ammonia

Green water is a single celled algae that lives in the water. It usually appears as greenish murky water. Ammonia spikes usually cause green water. 50 -70 percent water changes can help get rid of the ammonia and green water. Make sure you have beneficial bacteria in your aquarium to kill ammonia.





Green Spot Algae

Green spot algae

Green spot algae usually appears as green spots on glass and slow growing plants like anubias. Low phosphate levels, low co2, or poor water flow causes this algae. Treatments include raising phosphate levels (not the best), adding more water flow to your aquarium, or adding co2. If you don’t want to buy pressurized co2, raise the light fixture or lower it.




Black Brush Algae

Black brush algae or BBA appears as bushy, hairy looking algae

Black brush algae has a bushy appearance. It grows in a dark brown or black color. Low co2 (not balanced with lighting) is the most common cause of this algae. If you have you have low light which doesn’t need co2, it’s because of to much changes in the amount of co2 you have. To fix it, raising co2 levels can help. If you have low lighting, too many water changes change the amount of co2 you have. New water you put in your aquarium after your water change has lots of co2. The big amount of co2 grows BBA faster than growing plants (not like this in a co2 injected aquarium). Not doing water changes for a while and doing some h202 treatments or overdosing excel kills the algae. Siamese algae eaters like to eat BBA algae too.





Green Hair Algae

Green hair or fuzz algae taking over plant leaves

Green hair or fuzz algae usually grows on plant leaves and sometimes decorations. It grows in small strands of green hair. It usually grows when plants aren’t getting enough nutrients or if co2 is low. Raising co2 can help. h202 treatments or overdosing excel can get rid of this. It can sometimes be hard to get rid of so be careful. American flag fish love eating this algae but not many fish stores sell them.





There are many other species of algae. The species above are the most common ones.

  • Amir

    I always have algae problems with my tank. I noticed if I move my tank away from direct sun light, it helps reduce algae growth.