Aquascaper’s Guide to an Algae-Free Tank
Written by: Gracie Mandel and Team Buce Plant
Algae, (or as some of our British friends pronounce it “Al-Guee”), is a pain that almost every aquascaper or aquarium-keeper in the hobby will experience at one point. You invest your time, money, and patience into building a beautiful landscape of aquarium plants and animals, just to be bombarded the unexpected nuisance of an algae bloom. Now, you find yourself with the ultimate predicament: how to get rid of algae.
But, you may have forgotten the most important aspect of keeping a planted tank; research. With proper research, you can ward-off the worst types of algae. This, my friends, is the key. Prevention.
Photo credit: Reddit user u/onlinetiger
Yes, I can see your eyes rolling. “Okay, but I am here because this disgusting green algae is already all over my plants, hardscape, glass, etc.” Well, don’t feel bad. It’s not time to quit. Don’t throw away your hard work and start a knitting club instead. Getting rid of algae may not be pretty, fun, or…dry, but there are ways to get rid of almost all aquarium algae forms and prevent it from coming back.
In this article, I will cover every preventative measure that can stop every type of algae in the aquarium (all forms), as well as extreme measures to remove the worst types once they have struck.
These tips apply to almost every type of algae you may encounter:
Let’s start with prevention. 90% of all algae can be prevented.
However, that does not make it any less scary. Algae is actually one of the longest-lived life forms on this planet, and it has evolved! There are single cell versions, and complex versions (when you go out for sushi… your seaweed wrap is actually a form of algae). It is the single-cell versions that we want to prevent and eradicate.
KNOW THE ROOT CAUSES
There are truthfully two main components that can cause almost all algae in the fish tank. And they must be avoided from the first day you begin your planted tank:
Poor Tank Maintenance and Poor Aquatic Plant Growth.
The early stages of your tank are the most dangerous when it comes to the formation of algae. Algae is actually a type of plant in and of itself. It uses the same nutrients, light, and oxygen as your beautiful plants.
This is where the importance of tank maintenance comes in.
KEEP UP WITH MAINTENANCE EARLY ON!
Heads up: your brand-new tank is naturally out of balance.
Your beneficial bacteria has not cycled throughout your tank yet. (Learn more about the importance of a cycled tank HERE) The plants you have so delicately placed have not had time to establish themselves and root. Ammonia is all over the place, and can spike at any time.
This is all normal, but must be monitored. Unfortunately, algae loves ammonia. The way to do this is with a few techniques:
WATER CHANGES. LOTS OF THEM!
Ammonia spikes often happen with new setups due to the type of nutrient-rich plant soil you use, which is often full of nitrogen. Depending on the brand, when the soil becomes wet, large amounts of ammonia will leech out.
- Hint: UNS Controsoil is the perfect solution for those who want good plant growth without the headache of excessive ammonia.
Ammonia spikes are dangerous to livestock and give algae the opportunity to grow. Your plants can utilize ammonia to grow, but if they are unable to uptake it quickly enough, algae will use it first.
You can dilute the amount of ammonia present in your water by doing water changes on your new planted tank every day at least 50% for the first week, then decreasing to every other day, and so on for about four weeks.
PLANT HEAVILY FROM THE START
This is an important tip to preventing algae. Use as many plants as possible in your tank setup, and adding a majority of fast-growing plants will help as well.
- Tip: “Helper Plants” are plants that you can add low-cost, rapid-growing weeds (such as Parrot’s Feather), stem plants, and floating plants in the beginning. Keep in mind that you don’t necessarily have to keep them in your tank forever.
Due to the fast-growing nature of these plants, they will use up the light and nutrients before algae gets a chance to. Floating plants also help to shade excess light and have unlimited access to CO2 in the air.
It’s also smart to use plants that are grown already in their submersed form (under water). This will ease their transition to your water parameters, lessening the energy-expenditure they would have to use on transformation (vs. plants grown hydroponically out of water). This can also be achieved by using trimmings of plants already established in your other tanks, or tissue culture plants growing in a nutrient rich media, which will be readily adapted.
- Tip: Tissue culture plants are all created in sterile labs. This means you don’t have to worry about any hitch hikers when adding them to your tank, such as algae, snails, or pesticides.
Photo Credit: @mn_aquascape on Instagram
LED AQUARIUM LIGHTING
Make sure to buy appropriate LED lighting for your plants/setup! If your lighting is too bright, or stays on for too long, this can cause algae to grow. Use a timer and/or a dimmer to keep light consistent and not too bright. On the other hand, if the light is too weak or not on for long enough, your plants’ growth may be stunted. Most plants are happy with 6-8 hours of light.
Twinstar features a variety of aquarium lights for different tanks’ needs ranging from low-tech to high-tech. You can check out a Twinstar Light comparison guide by clicking HERE.
Note that the stronger your lighting is, the more CO2 and nutrients you will need to add to your tank (and you need a lot of plants to consume this!) With this in mind, if you have a low-tech tank with slow-growing plants, make sure you keep your light levels low, have appropriate nutrients, good flow/oxygen, and still plant heavily.
The warmer the water in your aquarium, the greater chance of algae thriving. Living organisms (algae) have a faster metabolism in warmer temperatures. If your tank inhabitants require higher than average temperatures, increase your water change frequency.
Do your best to keep your water temperature at the lowest acceptable level to keep your living inhabitants healthy (our pets are the main priority, of course). Most aquarium plants will thrive in temperatures between 72°F – 78°F.
It is obvious that frequent water changes, and tank maintenance are necessary, but many people forget about their filters. An old dirty filter, filled with debris and mulm (organic waste) can host bacteria. This bacteria consumes oxygen which promotes algae. (Never rinse your filter media in chlorinated water, only in tank or fresh water).
DON’T FORGET TO FERTILIZE
It is commonly thought that the more fertilizer used, the higher chance of algae. However, if you have planted densely enough, you need to feed your plants the nutrients necessary to grow! A lack of fertilization can cause nutrient deficiencies. Rotting/dying leaves can be a source of algae formation. Your plants have the ability to take in slightly more fertilizer than typically needed (don’t go crazy, though!).
Okay… we addressed the root causes and prevention of algae, so how do we get rid of it?
Simply stated, manually remove as much visible algae as you can!
There are many tools you can use for this process. A regular toothbrush is a great option, as is a wire brush often used to clean filter tubing. Additionally; your fingers, UNS pinsettes, sponges, credit cards, and aquarium algae scrapers can be utilized.
If a plant is completely overtaken by algae and cannot be salvaged, either completely take it out or simply trim off the affected areas.
After manual removal, make sure you do a large water change, and clean your filter to get rid of the excess waste and algae spores you have released.
Again, add more healthy plants if possible.
USE PROPER CIRCULATION
If you are utilizing CO2 injection, it must be dispersed throughout the entire tank in order to reach every plant. Add an extra filter, and airstone, or a water pump.
This will also help contribute to a well circulated tank (also known as a well-oxygenated tank.) Remember that stagnant water breeds algae. Make sure your tank’s water column has proper circulation!
ADD A CLEAN UP CREW
For some extra help, add some algae eaters to your planted aquarium. I actually recommend adding only shrimp and/or snails as your clean up crew. They will munch on the algae and produce minimal waste.
I do not recommend fish such as plecos in severe cases, as they will end up adding to the waste, potentially worsening the algae.
Almost all algae can be eradicated using these methods. However, if the algae is especially stubborn, or you have Blue Green Algae/Cyanobacteria, you may need to take more drastic measures:
Some severe cases of algal growth will require full darkness. You can starve the algae by completely blacking out your planted tank.
- Before doing so, make sure you have manually removed as much algae as possible, have done a large water change, and obviously turned off your aquarium lights. Tip: BGA starts off in the substrate of the aquarium. Make sure you do a thorough substrate/soil siphoning.
- Drape a towel, blanket, or dark paper completely around your tank.
- Keep the tank in absolute darkness for 72 hours.
- Your fish will be okay for 72 hours without feeding. DO NOT PEEK! You may add an extra airstone if you are worried about lack of oxygen.
- After removing the dark covering, repeat the maintenance you performed before the blackout.
Any light, including ambient light hitting the substrate could start BGA. Some people will use black tape at the substrate line to avoid this. Make sure your tank is not in a location that is affected by ambient light. If you cannot move it, consider covering the windows allowing this light in. BGA may also be caused by low nitrogen levels, so test your water to make sure your plants are receiving enough nitrates (fertilization).
There are several ways to spot treat algae in the aquarium, but a favorite is the use of 3% hydrogen peroxide (H2O2). Here is a quick step-by-step guide to safely spot treating with H202:
- Turn off your filters first, as keeping it running can affect your bacteria colony.
- Use approximately 3ml for every 1 gallon of water. Fill a syringe with the hydrogen peroxide and apply as needed on affected areas. You can also drain your tank completely and fill a spray bottle with the hydrogen peroxide, then spray the affected areas.
- You will notice bubbles forming on the treated areas – don’t be alarmed! This is normal and completely harmless to your tank and its inhabitants.
- Keep your filters off for about twenty minutes after treating.
The algae should start dying off within 24 hours. You may notice a change of color. This treatment may also need to be repeated until the algae has been removed.
NUKING (LAST RESORT)
We understand that some algae problems are persistent and drastic measures are needed. Please keep in mind that we only recommended nuking if the tank is absolutely infested and you’re ready for a fresh start! For this process, we recommend using either 10% bleach or 3% hydrogen peroxide.
- Remove ALL your tank inhabitants (including plants) to be on the safe side. Your plants will need to be treated separately. Click here to learn more about bleach dipping your plants.
- Remove filter media from your filter to save beneficial bacteria. Store media in cycled aquarium water with an air stone during this process.
- Treat the entire tank with 3% hydrogen peroxide or 10% bleach. Leave the solution in the tank for a 2-3 hours with the filter running to keep up circulation.
- Drain and refill the tank at least 3 times to remove any remaining traces of bleach/hydrogen peroxide and algae.
- After thoroughly cleaning the tank and bleach dipping your plants, you may introduce your plants, livestock, and filter media back into your tank.
I understand that getting rid of algae and keeping it at bay can be stressful for all aquascapers! Keep these preventative measures and extreme measures to remove the worst types of algae in mind. Has this article helped you? Please leave a comment below!
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Susan – November 9, 2022
I am 70 years old and have had fish tank since I was a child. And I’ve dealt with algae since I was a child. But I now have an Aussie tank that hangs on my bedroom wall so I can’t take it down and take it outside and scrub it out with the hose and bring it back in the house. And I hate algae. I am now dealing with it one more time. Thank you for this wonderful article and the new ways of dealing with algae.I just ordered plants from you and I can’t wait to get them in so I’m hoping my floaters will also help with my algae problem. Though my problem isn’t extreme I still hate it and I’m hoping that with water changes and lots of scrubbing I can eradicate it as quickly as it appeared.
Harold Green – June 1, 2021
I have spot treated both black beard algae and stringy filamentous algae with Seachem Flourish Excel. This will kill those while the areas are small. You just have to be careful not to overdose. The benefit is that plants will be able to use the bioavailable carbon for their own growth.