How to Avoid Algae in an Aquarium

Algae is a type of aquatic plant that feeds on sunlight and chemical nutrients in their environment. Algae is invisible in small amounts, and your tank almost certainly has small traces of algae in it right now. But once the algae builds up and accumulates, it can cloud the water and cover up the glass. It can be quite frustrating to feel like you’re constantly cleaning when you should be enjoying your aquarium. Luckily, if you’re diligent about changing your water and keeping light levels low, it is unlikely that you’ll have to deal with algae in your aquarium. The algae solutions in this article are identical for fresh and saltwater tanks, with the exception of the types of fish, snails, and shrimp that you can buy to eat the algae in your tank.^[1]

[Edit]Steps

[Edit]Controlling the Light

1. Place your tank so that it’s not facing any windows. Placing your aquarium in front of large windows results in unwanted light that you can’t control. In addition, natural light feeds algae. To avoid this, set your aquarium away from large windows and out of the path of direct light. Similarly, keep your tank out of the rooms in your home that have really bright lights in the ceiling and are often left on for long periods of time.^[2]
   
   • Indirect light is perfectly fine and can actually help your fish know when it’s daytime.
2. Keep artificial lights to 4-6 hours a day to avoid feeding algae. Since algae uses photosynthesis to grow, the amount of light your tank receives will impact the likelihood of algae growing in your tank. While exposing fish to light during the day is important, you can certainly cut down on the amount of light you use without harming your fish. Keeping artificial lights on for less than 6 hours a day is a great way to prevent algae from growing.^[3]
   
   • You can turn the lights on for your aquarium at any point during the daytime. So long as you’re consistent, your fish will adapt their circadian rhythms to your light.
   • If you have live plants, make sure they get at least 10 hours of light a day. Fortunately, live plants are really efficient at combating algae, so you don’t need to worry about light levels as much if you have live plants.
3. Replace all aquarium lights after 1.5 years to avoid deteriorating lighting. Aquarium lighting is specifically designed to provide plants and fish with light in a concentrated section of the light spectrum. As aquarium lights wear down over time, the light they emit can shift to a different part of the light spectrum and promote algae growth. To prevent this, replace aquarium lighting every 1.5-2 years, regardless of whether the light appears to be functioning correctly or not.^[4]
   
   • This is particularly important for fluorescent bulbs, since they tend to change dramatically when they’re wearing down.
   • Replace any lights that look dimmer than they were when you first installed them. Dim bulbs are typically a sign of a dying aquarium light.

[Edit]Monitoring and Cleaning the Water

1. Check your filter every 1-2 days to ensure it’s working properly. Every 1-2 days, lift your tank cover up and inspect the filter carefully. Check the trap on the filter and remove any obstructions. Check the flow of water when it’s running to make sure there’s a steady stream of fresh water. If your filter ever stops running, replace it as soon as possible to avoid giving the algae time to build up.^[5]
   
   • Rinse your filter out under a steady stream of water if it has fish waste or algae on it. Algae can typically be scraped away completely with a razor blade or the tines of a fork.
   • Filters will typically do a very good job of removing algae on their own. If there is any part of the tank that you want to upgrade to prevent algae, get a higher-end filter.
2. Replace 25% of the water every 1-2 weeks. Replacing all of the water all at once can shock your fish and plants, since you’re completely changing the environment at once. However, if you never replace the water, the fish waste and algae can build up quite dramatically.^[6] Drain 25% of the water out once every 1-2 weeks and replace it with new water to ensure that large amounts of algae don’t build up over time.^[7]
   
   • Use whatever kind of water your tank normally uses to replace the old water. Most fish will thrive with purified mineral water. Alternatively, you can use tap water that has been conditioned to remove the chlorine.
   • It’s better for the fish if you don’t change the water out all at once. Even if it looks cleaner, many fish will struggle with a brand new environment.
3. Clean your aquarium glass weekly with an algae scraper to keep it clean. An algae scraper is basically a razor blade attached to a long handle. Scraping the inside of the glass regularly is a great way to remove any algae that you can’t see and prevent buildup over time. Do this at least once a week to ensure that your glass stays clean and clear.^[8]
   
   • If you have an acrylic tank, make sure that you get a scraper designed specifically for acrylic.
4. Use an algae magnet to clean your glass regularly without getting wet. An algae magnet is a cleaning pad with a heavy-duty magnet attached to it. It connects to a magnet on the outside of the tank which allows you to clean the interior glass without getting wet. Purchase an algae magnet and move it around the glass to spot clean algae and remove thin layers that may not be immediately visible to the naked eye.^[9]
   
   • If you have an acrylic tank, be sure to get an algae magnet that is designed specifically for acrylic.
5. Test and modify the tank’s nitrate and phosphate levels every 6-12 months. Purchase nitrate and phosphate testing kits to check your water every 6-12 months. Take a water sample in a test tube and pour the testing kit’s solution into the tube. The water will change color and you can compare it to the color chart that comes with your kit. Phosphate should never exceed 0.03 parts per million (ppm), while nitrate should levels should typically stay below 0.07 ppm.^[10]
   
   • Nitrate and phosphate are the 2 chemicals that lead directly to algae growth. Test your water every couple of months to ensure that the levels are safe.

[Edit]Creating an Algae-Free Ecosystem

1. Add some algae-eating fish to snack on any algae that appears. There are plenty of fish, shrimp, and snails that feed on algae particles and won’t bother other creatures in your tank. Introducing these creatures to your tank are an excellent way to prevent algae from accumulating in large amounts. Pick up 2-10 algae eaters based on the size of your tank and let them feed on any algae that grows.^[11]
   
   • A tank typically requires 3-4 algae eaters. Add another 1-2 algae eater for every on top of that.
   • The most popular algae eater is the hillstream loach, which is great at getting algae off of glass. Other options include Amano shrimp, angelfish, nerite snails, cherry shrimp, and otocinclus fish.
   • Before adding new fish, research the breeds that are already in your tank to ensure that they won’t be hostile towards your new algae eaters.
   • The creatures you buy to eat algae must be appropriate for the type of water in your tank. For example, the hillstream loach can only live in freshwater, while angelfish can only live in saltwater.
2. Use live plants instead of plastic plants to compete with the algae. Live plants will compete with algae for the nitrates and phosphates in your water. This is a great way to naturally cut down on algae levels without dramatically changing anything in your tank. Most fish prefer hanging out in live plants anyway! If you’re using plastic plants, replace them with live varieties to limit the amount of algae in your tank.^[12]
   
   • For freshwater tanks, java moss, coontail, and water wisteria are resilient, solid options. For saltwater tanks, mangroves, Halimeda, and green finger algae are great choices.
   • Basically every live plant will compete with algae. You don’t need to buy any special kind of algae-fighting plant.
3. Blackout your tank once every 6-12 months to reset algae levels. Blacking a tank out refers to the process of removing all light sources for 24-48 hours to kill off any algae that may be present in the tank. To do this, turn your tank lights off and cover the tank with a dark blanket or fabric. Leave the lights off for 24-48 hours before returning to normal conditions. This will starve all of the algae and kill it off. Change the water out completely over the course of the next 2-3 weeks to remove any algae residue in the water. Change out 20% of the water every 2-3 days until you’ve completely replaced the old water to get rid of the dead algae.^[13]
   
   • Continue to feed your fish while your tank is blacked out.
   • If you have live plants, do not exceed 36 consecutive hours of blackout conditions.

[Edit]References

1. ↑ https://www.ratemyfishtank.com/blog/the-benefits-of-algae-in-saltwater-tanks
2. ↑ https://www.petcoach.co/article/top-10-tips-for-controlling-algae-growth-in-your-aquarium/
3. ↑ https://www.petcoach.co/article/top-10-tips-for-controlling-algae-growth-in-your-aquarium/
4. ↑ https://youtu.be/p8FcOGczsFQ?t=86
5. ↑ [v160978_b02]. 27 August 2019.
6. ↑ [v160978_b02]. 27 August 2019.
7. ↑ https://youtu.be/p8FcOGczsFQ?t=128
8. ↑ https://www.petcoach.co/article/top-10-tips-for-controlling-algae-growth-in-your-aquarium/
9. ↑ https://youtu.be/-OUSDY9kYlo?t=49
10. ↑ https://youtu.be/p8FcOGczsFQ?t=157
11. ↑ https://youtu.be/h94Jp82Dk_U?t=25
12. ↑ https://www.csmonitor.com/The-Culture/Gardening/diggin-it/2010/0316/Plants-that-fight-algae-in-the-water-garden
13. ↑ https://youtu.be/k6rmkyh5j4A?t=401