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Blackout - fight against algae without chemicals

Blackout - fight against algae without chemicals

Blackout is becoming more and more popular and well-known in our hobby. Its success lies in its simplicity and "chemical-free" solution. If we follow the proper steps, there is no danger to any living thing in the aquarium except algae.

Which algae can be treated with a blackout?

Blackouts effectively remove brown algae, green algae, green dot algae, and filamentous algae with excellent efficiency. Even with cyano (BGA) algae, you can use it to treat them successfully.

For which algae is the treatment less effective?

Some algae can stubbornly resist. These are the black brush algae (BBA) and the staghorn algae. It is worth continuing with Excel or Carbo algae treatments after the blackout or using a more extended blackout period for these algae types.

What exactly is a blackout?

The theory is based on the fact that, compared to plants, algae can only store a minimal amount of resources, so they need regular light to get energy through photosynthesis. If we deprive them of light, they will perish in a short time. However, our plants will survive the dark period by utilizing the nutrients stored in their roots and leaves.

The dark treatment is recommended for a maximum of 7 days. In most cases, 3-5 days of blackout brings excellent results and is less stressful to our aquatic plants. It is important to note that a blackout is not only about turning off the lamp. We completely block the aquarium from the environment light with a cardboard sheet or a dark blanket.

Main steps of blackout cure

  1. Perform a 50% water change while removing as many algae as possible from the water.
  2. Stop the CO2 injection.
  3. Ventilation of the water is essential, so either uses an air pump or do more water surface movement with the filter. (The water filter must work continuously during the treatment)
  4. Do not feed fish or shrimps during the treatment!
  5. Do not use plant fertilizers during the blackout!
  6. Sometimes we can take a look to see if everything is okay, but rest assured, everything will be fine;)
  7. On day 3, please turn on the lamp for a few minutes and check the progress. If everything is good, continue treatment until day 5.
  8. At the end of the treatment, remove any visible dead algae and do a 50% water change. Only clean the filter after a few days.
  9. Turn on the lights, but set the lighting time to only 4-5 hours for 1-2 weeks!
  10. Switch on the CO2 supply. (make sure to adjust for the updated lighting hours)
  11. You can feed our fish again and start providing fertilizers to the aquarium plants.

aquarium blackout treatment  

What to expect after the blackout?

Once we remove the blanket, it is normal that the plants will look weaker. Their color becomes paler, visibly elongating in search of life-giving light. In a couple of weeks, they will thrive just as before the treatment. Moreover, they will be more beautiful once they are freed from the grip of algae.

Our fish and shrimps will quickly accommodate the light. We don't have to be afraid of hurting them.

How long will the treatment be effective?

Blackout is a very effective symptomatic treatment, but we need to determine what triggered the outbreak! Otherwise, the algae will move back to our aquarium slowly.

Hemianthus C. Cuba carpet in the aquarium

What could be the causes of algae growth?

In most cases, the excess light source is too intense, or the lighting period lasts too long. If you feel this is a reason, reduce the brightness or the number of lighting hours.

Often, excessive accumulation of organic matter can cause algae problems. Do not neglect water changes, substrate cleanings, and reduce the amount of fish food. Ensure you have a filter of the right size and efficiency in your aquarium to handle the task.

Finally, the most common causes are under-or overdoses of plant nutrients.

Algae eater fish

How often can I have a blackout course?

The condition of our plants determines how densely it can be done, as our fish and shrimp are not disturbed by the lack of light. We recommend allowing our plants to regenerate for at least two weeks after each dark treatment.

Any questions left about blackout?

If you need help with your aquarium or algae problems, please contact our customer service, and we will be happy to help.

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