Getting Rid of Aquarium Algae

Green algae in aquarium

Getting rid of algae in aquariums is a multistep process which requires time. Resist using algaecides as they only cover up the symptoms instead of eliminating the conditions that cause algae growth.

Once algae become a problem in the aquarium, a water test will not always be conclusive in determining the cause of the outbreak or algae bloom.

For example, algae take up nitrates and phosphates. If either or both are at high levels in the fish tank, then this is certainly a cause for algae problems.

However, a low reading of nitrate or phosphate in an algae infested aquarium can be misleading. Because algae is constantly taking up these nutrients as a food source and fuel for growth, getting an accurate reading can be difficult. Nitrate, more often then phosphate, is usually abundant in a problem tank.

Follow these steps to get rid of algae in the aquarium:

  • Clean the gravel with a siphon in order to remove waste and debris
  • Clean the aquarium filters. Just rinse under cool water. DO NOT USE SOAP!
  • Increase water flow with a higher rated filter or supplemental power heads
  • Reduce feeding of fish to as little as once every other day
  • Replace light bulbs if older than 6 months as their light spectrum changes as they age, often favoring algae growth
  • Use a nitrate remover. Nitrate are a primary food source for algae and a leading cause of algae outbreaks in aquariums
  • Remove phosphates
  • Discontinue any supplements and fertilizers

The best way to prevent algae is to be pro-active

Eventually every aquarium will experience some level of algae growth. Acting on the steps outlined above can avert larger problems.

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Hi. Brown algae problem. I clean and part change the tank water often. But within a week It’s back. It gets everywhere. Help! Thanks, Shaun.

You shouldn’t clean the aquarium or change the water too frequently. This may disturb beneficial bacteria colonies which are needed to keep the aquarium balanced and clean. Further, make sure you don’t overfeed your fish. Uneaten fish food, as well as fish excrement eventually ends up being converted into nitrate, which is fuel for algae growth. You can safely feed only once a day, sparingly at that. It’s even ok to feed once every other day while attempting to clear algae from the aquarium. Fish have a slow digestive metabolism and don’t require large amounts of food. They will also… Read more »


I have a salt water tank 38g and I went out of town and my husband was to feed them, will I feed them one time a day and everything has been just find so now I have green algae all over my rocks and I want to get new rock and switch to sand so can I do a water change bring it down low and take out the rocks and gravel and leave the old filters for some good bacteria and my bio wheels. would that work.


Hello! Very informative post! Agree that preventing algae is the best way. Adding algae eaters can also help.


You should also use a UV sterilizer to prevent an algae outbreak! Personal recommendation when it comes to combating algae

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