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Fish Tank Problems: How to Get Rid of Red Algae in Your Aquarium

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My Red Algae Problem


Red Algae Problem

Luckily for freshwater aquarium enthusiasts, most red algae problems are most likely to occur in saltwater tanks. This algae is most commonly the result of a high level of nitrates and phosphates in your aquarium which can be caused by having an abundance of waste from your fish or leftover food. It can also come from poor light bulbs or overexposure to lights.

You will see the red algae appear first on your live sand and walls of the aquarium. This is your first sign to get it out of there. The sooner you start taking care of the problem the easier it will be to get rid of this pest for good.

Fixing Red Algae Problem Without Chemicals

The first thing you should do is scrape and scoop out all of the red algae appearing on the sides of your fish tank. The best thing to use is one of the hand-held, long-handled scrapers which you can find online or at the fish store (the good ones usually go for about $10-15).

After clearing the sides of your tank you want to get the algae out of your sand. This is more difficult because it usually starts growing between the sand and the wall of your aquarium. The easiest way to do this is to use your finger and run in between the wall and sand in your aquarium and then use your scraper so you don't miss anything. You will then want to move onto the red algae on the top of your sand. Use a net to scoop and sift the algae off of the sand until you have gotten rid of all of it.

Once your tank has been cleaned of all the red algae, turn your tank light off for one to two days. By doing so you are taking away the light that helps the bacteria grow. Still do everything else as you normally do but avoid over-feeding your fish. As a rule of thumb the food you give your fish should be eaten in about ten seconds or you are giving them too much. If you feed them live fish along with things like frozen shrimp, stick to the non-live food during this process.

Chemicals To Get Rid Of Red Algae

There are many red algae treatments on the market. Most of these are drops that you add to your tank water and solve your problem fairly easily. The first thing you want to do before adding any chemicals is to follow the above procedure for treating the red algae without chemicals so the mixture will focus on anything you might have missed.

The procedure for using the chemicals varies slightly between brands but most are very similar. From my experience, after physically removing the red algae I added the drops based on the amount of water in my tank (50 gallons). Then turned the lights on and turned all pumps, filters, and my skimmer off. The red algae remains floated to the top where I scooped them out and problem solved. I only had to wait one day for the process to work.

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One thing I was made aware of by my local aquarium expert is that when you use chemicals to get rid of red algae, you want to add an oxygen stone. Apparently some of the brands do not tell you this in their instructions, however, it is vital to the health of your fish as the chemicals take the oxygen away.

Avoid Red Algae In Your Aquarium

  • Do not overfeed your fish.
  • Do not leave your tank light on for more than 8 hours a day.
  • Make sure your bulbs stay fairly new and that they are putting out the correct wattage and light color.
  • Get a test kit and regularly test your water for an abundance of nitrates and phosphates.
  • Change your filters and clean the walls of your tank when necessary.
  • Speak to your local aquarium expert and be informed about red algae and other problems you might likely encounter.

More About Saltwater Aquariums


tigerbaby777 from Nampa on January 20, 2012:

Very good advice!

Sadie (author) from U.S. on January 18, 2012:

Thank you Kris! It's frustrating and there isn't a lot of good content out there.

Kris Heeter from Indiana on January 18, 2012:

It's been awhile since I've had a salt water aquarium, but I remember fighting the algae was never fun. These tips are very useful! Good hub:)

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