How to get rid of algae in fish tanks naturally? Natural algae, to some extent, in your fish tank can be beneficial. They utilize ammonia as a food source, being a food source for fish and invertebrates and even producing vital oxygen via photosynthesis.
There are different types of algae you may encounter, but green and brown are the most prevalent ones to find in an aquarium. Unfortunately, although even these algae aren’t harmful to fish or plants, they’re still aesthetically unpleasing.
But when there are many algae in an aquarium, it may actually be harmful to fish. It can cause problems by blocking the filter, raising the pH too high, and starving oxygen at night.
So it’s best to get rid of algae!
Algaecides can be used to remove algae from aquariums, but they can create a further imbalance in water and not cure the source of the algae problem. The result is that it comes back again with the same conditions causing this issue.
Everyone knows that prevention is better than cure! So, if you can’t eliminate the cause of algae growth, the problem will never be solved.
I explained some simple methods below – how to get rid of algae in fish tanks naturally.
Why Does My Fish Tank Have So Many Algae?
Algae is caused by an imbalance of nutrients and lighting in your aquarium, but achieving a perfectly balanced tank is nearly impossible.
If you give your aquarium plants too much light and not enough nutrients, algae will take advantage of the excess lighting and multiply.
If you provide a lot of nutrients but not enough light to your aquarium plants, then algae will consume nutrients and grow faster than the plant.
So, getting rid of algae ultimately is not possible, but you can keep them in control!
How To Get Rid Of Algae In Fish Tank Naturally (06 Ways)
Reduce The Light
Excessive light in a fish tank can cause the growth of nuisance algae. If there are live plants, limit lighting to 8 – 10 hours per day. And if you don’t have plants, turn them off entirely unless you’re not playing with your pets.
Fish, just like people, need a day/night cycle to be healthy. However, in the wild, most tropical fish don’t have massive lights blaring down on them as they do in your tank. Instead, the dim light of daytime is an approximation for what they experience back home; their rivers and lakes are naturally dark at night since there isn’t artificial lighting coming from above.

Algae outbreaks can be stopped by turning off the aquarium lights and creating complete darkness for a few days. At this time, algae have difficulty growing because they are not receiving light or nutrients from photosynthesis.
However, plants that survive in these conditions will eventually rebound once the lighting is restored to their original settings.
Avoid Direct Sunlight
Try to place your fish tank somewhere that doesn’t get too much sunlight because this will cause algae growth.
Algae is one of the fastest-growing organisms on Earth. Given an adequate amount of sunlight, it can double in size every few hours!

It’s not good for fish to be exposed directly to the sun either. The increased temperatures cause unnecessary stress and can deteriorate their health, so it is best to keep them out of direct sunlight as much as possible.
Employ Natural Algae Eaters
Some owners with algae problems choose to purchase fish or creatures that can eat the algae. It is a good solution, indeed!
If you’re looking for an algae-eater, then get some tropical freshwater fish! Smaller tanks can use Otocinclus catfish and Algae eating shrimp. For larger tanks, consider Mollies, Siamese algae eaters, and Bristlenose Catfish.
Related Read: 15 Best Algae Eaters (Fish, Snail, and Shrimp)

These creatures will graze on green slime in a tank without hesitation!
However, they may prevent it from getting worse in tanks with minimal growth. But these animals cannot solve major issues of green hair and slime-covered leaves for at least two reasons:
- They do not eliminate root causes
- Their appetites don’t work fast enough to keep up with a significant outbreak.
Plant Heavily
Some experts have found that planting heavily with healthy, fast-growing aquatic plants can help to fight algae naturally. In addition, they recommend using a fixed photoperiod of 8 – 10 hours while fertilizing regularly and employing algae-eater fish in the tank as well.

Plants in your fish tank can limit algae growth by competing for the same food sources. However, it is believed that some plants give off natural substances that prevent algae growth.
When planted aquariums are done right, they can be perfect little ecosystems that meet the needs of fish and plants alike. When the balance is right, algae growth will be minimal.
Avoid Overfeeding
If you are overfeeding your fish, the food leftovers will fall into the tank and get sucked up by a filter in your aquarium, creating an increased chance for algae growth. This is because fish waste mixed with decaying fish food produces nutrients to fuel algae’s survival and growth.

A good rule of thumb is to feed no more than they will consume within 2 – 5 minutes, and make sure you give them a day off each week. In this way, you can limit algae growth and create a healthy environment for your fish.
Maintenance And Water Changes
A routine of weekly water changes and monthly cleanings will help control algae in the tank. All tanks accumulate wastes that are nutrients for algae—replacing a percentage of the water once a week reduces these nutrients and makes healthier conditions.

Each month requires rolling up your sleeves to vacuum the substrate, cleaning off decorations with hot water or vinegar solution, replacing the filter if needed before scraping it down with a toothbrush then rinsing everything in freshwater.
Take a hands-on approach to remove algae from your aquarium by using an algae pad or scraper. Use a siphon regularly to manually remove the dislodged algal cells from the aquarium.
How To Handle An Algae Bloom
If your tank water turns green all of a sudden, it’s likely an algae bloom. Water parameters change towards their favorable conditions, allow them to thrive, and can cause rapid growth! This isn’t as scary as it sounds because there are easy solutions.
If you cannot control the algae in your water, it could be because sudden changes have occurred that favor its growth. You first need to determine what caused this change so that you can take steps against future outbreaks of algae.
To fight the situation, simply perform what’s called a water change and introduce fresh, clean water into your tank to take away some of the nutrients that contribute to an alga bloom.
Different Types Of Algae Grow In Fish Tanks
Algae is a general term that refers to many different types of plant-like organisms, and it can cause problems in your water tank if not taken care of immediately. However, there are several types you need to know about as they relate specifically to algae inside an aquarium.
Brown Diatom Algae
Brown dust-like Diatom algae might cover your aquarium walls, substrate, and other surfaces. It can be easily rubbed off with an algae scrubber sponge; many animals like to eat it too! Diatom algal blooms are often caused by high levels of phosphates and silicates in newly planted tanks.

Black Beard Algae (BBA)
As the name suggests, BBA grows in thick clumps that usually have a dark or grey color. This alga loves to attach itself to driftwood and plants with no signs of stopping. If left unchecked, it can completely take over your aquarium within months, making it difficult for fish to survive!

Hair Algae
Algae that look like wet hair are categorized as ‘hair algae.’ These types of alga can be problematic because they overgrow or are hard to get rid of. They’re generally caused by excess nutrients such as iron, too much light, and insufficient nutrients.

Green Spot Algae (GSA)
Green Spot Algae looks like tiny, hard green spots on the aquarium walls and slower-growing plants that are very difficult to clean off. A lot of things can cause an outbreak, such as too much light or an imbalance in phosphate levels.

Blue-Green Algae (BGA)
Blue-green algae (BGA) is not actually an alga but rather a type of cyanobacteria that grows like a slimy blanket, coating the substrate and decor. It comes with such a distinct smell many fish keepers learn to recognize before it’s visible.

Final Words
From the perspective of an aquarium owner, I’ve learned a lot and hope to share some insights with you.
If you’ve been looking for a solution to this problem and want some tips on how to get rid of algae in fish tank naturally before it starts affecting your fish population – I hope you’ll find this article helpful.
If you have anything more to know, please leaves a comment below. Thanks for reading this article!
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Learning how to clean algae from fish tank glass is an essential skill that can be learned as part of the maintenance process of the aquarium. Thanks for writing this informative post! 🙂