How to Get Rid of Blue-Green Algae in Aquariums
Do you have a mysterious, blue-green slime taking over your aquarium? Or is there a strange smell coming from your fish tank and you can’t find the source? Blue-green algae might be a problem. This article will explain the causes of blue green algae and how you can eliminate it permanently.
What is Blue-Green Algaeee?
Blue-green alga (BGA) does not exist as an actual algae. It is actually a cyanobacteria, a group of bacteria that uses photosynthetics like plants. In freshwater aquariums, it’s known for its vivid blue-green color, but it can also appear in shades of brown, black, or even red. You may see it start off as a little spot of green algae that eventually grows into a thick slime stretched over your gravel, decorations, and plants. While cyanobacteria in aquariums does not usually harm fish, it can potentially kill your plants if their leaves are covered and can no longer photosynthesize light.
Another way to identify blue-green algae is by its distinct odor. People have described the smell as earthy, musty, swampy, and foul. Once you have learned to recognize the scent, it’s possible to detect cyanobacteria up to two weeks before it’s even visible in the fish tank.
Blue-green algae can be described as a type or photosynthetic bacteria.
What causes Cyanobacteria in Aquariums
Since cyanobacteria can have a devastating impact on the environment, many studies have been conducted to identify their causes. Although there is no clear answer, it is known that they are common in warm, slow-moving and nutrient-rich water. In the aquarium hobby, we have frequently seen blue-green algae pop up wherever organic waste has a chance to stagnate in certain areas of a fish tank. This can happen if:
– The current in the fish tank is too slow – Hardscape is blocking off a corner of the aquarium that also gets exposed to constant light – The substrate is collecting debris because the gravel hasn’t been vacuumed in a while and there are no animals to churn it
How do I get rid of blue-green algae naturally?
These possible causes are the basis for the first step: manually remove as much slime as you can using a siphon or toothbrush. Blue-green algae is not something animals like so your clean-up crew won’t be much help. Remove any excess nutrients by doing water changes more frequently, cleaning the filter regularly, and reducing the amount of fish or food going into the aquarium (if overfeeding is a problem). You can improve the water flow by adding a powerhead or a stronger filter.
Because Cyanobacteria relies on photosynthesis to generate energy, many people recommend that the aquarium lighting be turned off for at least three to seven days in order to starve the colony. However, this method can end up harming your plants (which also use photosynthesis) or causing spats among the fish. Plus, the blue-green algae often returns within a few weeks.
Cyanobacteria: Can Medicine Treat It?
People often have difficulty dealing with stubborn bacteria. Fortunately, it is weak against an antibiotic called Erythromycin. This medicine is safe for fish, plants, and invertebrates, and it will not harm the beneficial bacteria in your aquarium. Fritz Slime Out is our favorite, as it’s formulated to reduce cyanobacteria and not increase phosphate levels.
To begin treatment, scrub off as much of the blue-green algae as possible and remove it with a siphon. After vacuuming the substrate and refilling the tank, add one full dose of Slime Out (which is 1 packet per 25 gallons of water), and let the aquarium sit for 48 hours before doing a 25% water change. Add an air stone or other filtration that agitates the water surface to help ensure the fish have enough oxygen during the treatment. The earlier you treat the outbreak, the easier it is to eradicate. You may have to repeat the treatment multiple times if the blue green algae colony is large and thick.
If you address the underlying causes of cyanobacteria and treat it with Slime Out, you should have no problems getting rid of it in your fish tank. You can also find our complete guide to how to combat other types of algae in freshwater aquariums.