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Top 5 Ways to Clean Algae from Your Fish Tank

Algae is a natural part of the aquarium ecosystem because it helps to purify the water from toxic waste chemicals and serves as a food source for algae-eating fish and invertebrates. However, most people see it as an unwelcome guest since too much algae can obstruct your view of the fish tank and slow down healthy plant growth. Let’s talk about 5 easy methods for cleaning algae off your aquarium walls and decorations.

1. Use Tools to Manually Remove Algae

Physically removing algae with your own two hands is the first approach on our list because it produces immediate results without a lot of waiting, so let’s talk about the most efficient tools to have in your arsenal. If algae is coating your aquarium walls and making it hard to see your fish, an algae scrubber is the simplest way to wipe off the algae. This gentle sponge is made of non-toxic melamine foam and won’t scratch your glass and acrylic tanks. If you’re having trouble scraping off very tough algae like green spot algae, try using a Mag-Float Glass Cleaner with the matching scraper blades. These glass-safe blades easily cut through green spot algae like a hot knife through butter, saving you lots of time and effort when it comes to tank maintenance. (For acrylic fish tanks, please use the Mag-Float Acrylic Cleaner with the appropriate acrylic scraper blades.)

Aquarium Co-Op algae scrubber (pack of 3)

An algae scrubber can be used to wipe away algae from aquarium walls so that you have a clear view of your fish and plants.

A simple toothbrush is great for scrubbing hard-to-reach areas, aquarium decorations, hardscape, and even plant leaves. Certain hair algae types can be removed by grabbing the algae strands with the toothbrush bristles and twisting the toothbrush so that the algae winds up like spaghetti on a fork. Finally, if you see blue-green algae or brown diatom algae starting to coat the substrate, use an aquarium siphon to vacuum the gravel or sand.

hair algae in aquarium

Twirl a toothbrush in a mass of hair algae to easily detach it from plants, hardscape, or fish tank decor.

2. Get Help from Algae-Eating Animals

When algae growth starts overtaking a fish tank, many people automatically look for an algae eater to solve all their problems. The reason why we place them in second place on this list is because a) each algae-eating species only eats certain kinds of algae and b) they may not be able to completely clean your entire aquarium. However, they are a good second line of defense that can assist you in the fight against algae. For nano tanks, our favorites include nerite snails, amano shrimp, or a school of otocinclus catfish. For larger tanks, get some bristlenose plecos or Siamese algae eaters to cover more area. For additional suggestions, read about the top 10 algae eaters for freshwater aquariums.

siamese algae eater

The Siamese algae eater is an excellent clean-up crew member for bigger fish tanks, but make sure not to accidentally get its more aggressive lookalike, the Chinese algae eater.

3. Remove Excess Organics in the Tank

Algae is very adaptable and can readily consume the nitrogen compounds that come from fish poop, unhealthy leaves, uneaten fish food, and other organic materials. If your aquarium is fairly new and not well-established yet, it helps to eliminate any sources of nutrients that algae can take advantage of. If you have a planted tank, get a pair of scissors to trim off any dead or algae-covered leaves whenever you do a water change. Use a siphon to suck out rotting gunk from the ground, and feed the fish less if you find that they aren’t eating everything you give them within a few minutes.

Also, blue-green algae likes to grow where there are pockets of debris or “dead zones” in the aquarium, which can form if the current is too slow or there are a lot of large ornaments and hardscape blocking the way. Improve the water flow by moving the decorations around, filling in gaps between the hardscape with substrate, or getting a stronger filter or circulation pump.

4. Balance the Lighting and Nutrients

Ultimately, the most effective way to get rid of algae is addressing the root problem that is causing the algae to outcompete your plants. Algae uses the same resources (e.g., lighting and nutrients) as plants do to photosynthesize and grow, and if there is too much or too little of any of these building blocks, algae can take advantage of it at an uncontrollable rate.

To balance your planted tank, we recommend using an outlet timer to turn on your light for approximately 6-8 hours per day (as a starting point), and then gradually increase or decrease your nutrient levels as needed. If the nitrate level is above 50 ppm, do a water change to dilute the amount of nitrogen waste. If the nitrate level is below 20 ppm, dose the tank with Easy Green all-in-one fertilizer until the water reaches 20 ppm nitrate. Wait 2-3 weeks between each modification you make in lighting or nutrients levels so that you can see what impact it has on your plants and adjust accordingly. You will never be able to completely remove all traces of algae, so the goal is to minimize it until it’s barely noticeable.

5. Treat with an Algae Inhibitor

When it comes to chemical treatments, there’s a delicate balance between finding a remedy that is strong enough to affect the algae without harming the animals and plants in the fish tank. Liquid carbon is commonly sold as a fertilizer for aquarium plants, but it is more accurately an algae inhibitor that is known to reduce algae growth. Easy Carbon is our brand of liquid carbon that is safe for fish and invertebrates, and it has an easy-to-use pump head dispenser for quickly dosing your fish tanks. You can also get a pipette to directly squirt Easy Carbon on hard-to-remove patches of black beard algae (BBA) – one of the most difficult types of algae to get rid of. For more details on how to use liquid carbon, read the full article here.

black beard algae

Easy Carbon is effective against persistent algae outbreaks like BBA. When directly applying the chemical, temporarily turn off the filter to allow the treatment to “soak” on the algae for a few minutes.

The reason why chemical treatments are the last on our list is that we believe they are most helpful after you balance the lighting and nutrients in your planted aquarium. If you try to use algaecides in your tank without doing any of the previous four steps, the algae will keep growing back and the chemicals will have little to no impact. For more information on how to fight algae growth, read our article on the 6 most common types of algae.

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