Harmful algae and how to control them

Nowadays, harmful algae in the aquarium are becoming a familiar theme with the users. It does not depend on how professional you are in the aquarium, you will have to face to its appearance in your aquarium. What are algae? How to recognize algae in the aquarium and how to control it? Now, thuysinh.org would like to share all of our experiences so that you can consult and control it to protect and maintain the beauty of your aquarium. And we hope all of you will contribute and share your experiences with others.

What is harmful algae in the aquarium? Harmful algae in the aquarium are essentially defined as an alga which grows spontaneously under certain conditions. It will latch onto aquatic plants, rocks, even mosses in the aquarium. It can develop quite fastly,  which can uglify the general aesthetic of the aquarium. This uninvited algae can also destroy the aquarium in a short time. But when you have experiences to control it, algae in the aquarium is no longer a problem with you.

when you have experiences to control it, algae in the aquarium is no longer a problem with you.

Typical  types of algae in the aquarium:

1. Hair / Thread Algae
2. Green Water (Euglaena)
3. Green Spot (Choleochaete orbicularis)
4. Green Dust Algae (GDA)
5. Cladophora
6. Fuzz Algae
7. Blue Green (Cyanobacteria)
8. Brown Algae (Diatoms)
9. Black Brush/Beard (Rhodophyta)
10. Staghorn (Compsopogon sp.)

We will find out each type of algae and it’s causes and solutions.

1. Hair/Thread Algae

Cause:

-Iron in the aquarium is over 0.15 ppm, Which is mainly caused by lack of red aquatic plants in the aquarium.

Solution:

– Handle by hand: Use tweezers or hand to take them out as much as possible

– By fish: Sailfin Molly, platyfish, shrimp, molly fish … These fishes love to eat  Hair / Thread Algae. Sometimes, people grow algae to feed them.

Rebalance the nutrients in the aquarium: N (10-20ppm), P (0.5-2ppm), K (10-20ppm), Ca (10-30ppm), Mg (2-5ppm), Fe (1ppm ).

– Change 30% of the water once a week to prevent and limit Hair / Thread algae.

2. Green Water (Euglaena)

When your aquarium suddenly turns into blue, it is a warning sign of green algae. This alga is not harmful to aquatic plants and fishes in your aquarium, but it makes your aquarium looks seriously ugly. Because of this reason, green algae is also listed as algae which need to be removed.

Causes:

– Green algae is usually found in a new aquarium which is not balanced in nutrition and microorganism.

– This alga also appears when it was affected by some drugs and chemicals.

Solutions:

– Turn off the light, use thick fabric to cover the whole aquarium for 5 days: This is the best method to destroy this algae.

– Micro-filtration: a good micro-organism can eliminate Green Water.

– Use bactericidal UV light to destroy it.

– Filter cotton: increasing the amount of cotton filter will remove it.

– Change clear water: change clear water regularly within 1 or 2 weeks. This is the simplest method to remove this algae.

– Water fleas: Many people raise water fleas in the aquarium. Water fleas will eat Green Water, but this method is not highly recommended.

3. Green Spot (Choleochaete orbicularis)

Green spot can develop easily itself and it will latch onto the glass. This aglae can be removed easily.

Cause:

Lack of phosphate (PO4) – The main reason of green spot’s appearance.

Solution:

– Use razor: use stainless steel razor, or use a piece of plastic that is hard and sharp to remove Green Spot.

– Add phosphate (PO4) up to 0.5 – 2.0 ppm

– Use Nerita snail: This snail loves to eat green spot.

4. Green Dust Algae (GDA)

Green Dust Algae looks like a filament in the aquarium. GDA usually latches on the glass, stones, and aquatic plants, which causes the loss of aesthetics in the aquarium.

Cause:

– According to many people’s experiences, if you don’t change water regularly, the aquarium would become dirty and GDA would have a chance to appear.

Solutions:

– Use snail: red apple snail and Nerita will help you to reduce GDA

– Handle by hand: Use stainless steel blade or use dishwasher to remove this algae.

– Change 30% of water per week to limit GDA’s appearance.

5. Cladophora

Cladophora looks like Hair algae. But dealing with this algae is quite difficult.

Cause:

Many people use Moss Ball to decorate the aquarium, but Moss Ball has pathogens of Cladophora. This is why Cladophora appears. Cladophora is a type of algae that hardly be destroyed 100%.

Solution:

– Handle by hand: Use hand or brush to remove this algae.

– Use hydrogen peroxide: Use cylinder to pump hydrogen peroxide on places where are affected by Cladophora.

– Shrimps: Shrimps can eat Cladophora.

6. Fuzz Algae

Fuzz Algae usually grows on the edges of leaves. Fuzz Algae is curly and it grows in clusters.

Causes:

– Nutritional imbalance: Ensure nutrient content in aquariums: N (10-20ppm), P (0.5-2ppm), Ca (10-30ppm), Mg (2-5ppm), Fe (. 1ppm).

– Lack of CO2: Make sure that CO2 content is about 20-30ppm. If CO2 is over 20-30ppm, animals in the aquarium could be affected.

Solution:

– Maintain CO2 content and balance nutrient in the aquarium

Use some kinds of fishes which can eat Fuzz Algae: RC shrimp, Amano shrimp, Ottos, molly fish, Siamese algae – eater and some kinds of plecos fishes.

7. Blue Green (Cyanobacteria)

Blue Green can appear easily in the aquarium, especially in Vietnam. It is one of the most bacterial algae and it can easily cover everything in the aquarium. Blue Green is a photosynthetic organism. It is Blue-green, black or purple. It will absorb all nitrogen in the aquarium.  And especially, it smells like soil when being  removed out of the aquarium

Causes:

– Lack of nitrate.

– Organic content is redundant: usually caused by too much redundant food, or sometimes by dead fishes and rotten plants.

– Not provide enough light to the aquarium

– Water filter system is not good, microorganism can’t consume all organic substances in the aquarium.

Solutions:

– Increase Nitrates content up to 5ppm

– Growing some fast-develop-plants

– Turn the light off – Blue Green will die

– Change water regularly and reduce the amount of reductant food.

8. Brown Algae (Diatoms)

Brown algae are brown, viscous, and it usually latches on leaves, rocks and other hard objects. Brown algae usually appear when the aquarium do not be taken care of regularly or when the aquarium has too many redundant nutrients.

Causes:

– Redundant nutrients.

–  Newly set up aquarium

– Use light incorrectly or low-quality light.

Solutions:

– Use otto fish, RC shrimp, red apple snail or Nerita

– Change water regularly

– Change new light

9. Black Brush/Beard (Rhodophyta)

Black Brush/Beard is the most annoying algae among these algae listed above. It is black, red, gray, or brown. It can quickly cover all the edges of plants and even spread out on the ground.

Causes:

– Low pH: if you observe closely enough, you could see that Black Brush usually appear when normal fishes begin to weaken and die.

– Lack or redundancy of N, P, Fe. Nutrients should be balanced within: N (10-20ppm) P (0.5-2ppm), K (10-20ppm), Ca (10-30ppm), Mg (2-5ppm) Fe (.1ppm)

Solutions:

– Increase CO2: stimulating the growth of aquatic plants, which can absorb nutrients. These plants can reduce Black Brush.

– Add hydrogen peroxide directly on Black Brush

– Remove by hand, sometimes you can cut the whole plant.

– Use Siamese algae – eater, Yamato shrimp.  They are very useful in killing Black Brush.

– Change 30% of water each 2 days

10. Staghorn (Compsopogon sp.)

Staghorn is quite easy to control. It looks thin like deer’s horn. It usually lathes on leaves or equipment in the aquarium.

Causes:

– Nutritional imbalance.

– Lack of CO2.

Solutions:

– Remove by hand.

– Change water regularly

– Increase CO2 content.

Notes about aquatic algae:

– Most algae can be beaten by shrimps, apple snails, Nerita snails, Siamese algae – eater, etc. so if possible, enrich your aquatic animals by them.

– Change 30% of water regularly once or twice a week will help fishes and aquatic plants develop well.

– Do not use pesticides arbitrarily. It can make bad effects on aquatic animals and plants.

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