You’re not alone algae is one of the most common challenges in planted tanks, whether you’re using a 30cm cube or a ADA 180P. From green spot algae and filamentous algae hair algae to black beard algae and diatoms, each type appears due to different imbalances in light, nutrients, or CO₂. Identifying the algae correctly is the first step to solving the problem.
Why Algae Appears in Aquariums?
Algae is a natural part of any aquatic ecosystem, but it becomes a problem when the balance of light, nutrients, and CO₂ is off. Too much light, overfeeding, poor water circulation, or irregular maintenance can all trigger algae growth. In new tanks, like freshly set up aquariums, algae often appears during the early stages while the beneficial bacteria are still establishing. In mature setups, algae can result from excess nutrients (like nitrate and phosphate), inconsistent CO₂ levels, or outdated lighting systems.
1. Excessive Lighting
Too many hours of light per day, high-intensity lighting without proper plant balance, and direct sunlight hitting the tank can all contribute to excessive algae growth and disrupt the natural equilibrium of an aquarium.
2. Nutrient Imbalance
Too much nitrate or phosphate in the water, uneven or excessive fertilizer dosing, and a lack of nutrient uptake by plants can lead to imbalanced water chemistry, fueling unwanted algae growth and affecting overall aquarium health.
3. Inconsistent or Low CO₂ Levels
Unstable CO₂ injection, inadequate CO₂ levels for the plant mass, or the absence of CO₂ in high-tech planted tanks can hinder plant growth, create imbalances, and give algae a competitive advantage in the aquarium.
4. Poor Water Circulation
Dead spots in the tank where water doesn’t circulate, insufficient filtration, and weak flow from filters or pumps can lead to debris buildup, poor nutrient distribution, and stagnant conditions that encourage algae growth and harm overall tank health.
5. Infrequent Water Changes
Buildup of organic matter and nutrients, along with poor overall water quality, can create an ideal environment for algae to thrive while stressing fish and plants, ultimately disrupting the aquarium’s ecological balance.
6. New Tank Syndrome
Algae often appears in newly set up tanks during the cycling phase when beneficial bacteria are not yet fully established, leading to temporary imbalances in water chemistry that favor algae growth.
7. Too Few Plants or Slow-Growing Plants
Not having enough plant biomass to outcompete algae, especially when relying solely on slow growers like Anubias or mosses without incorporating fast-growing plants, can leave excess nutrients available for algae to exploit.
How to prevent from algae bloom?
1. Control Your Lighting
Limit lighting to 6–8 hours per day, avoid placing the tank in direct sunlight, use a timer to maintain a consistent photoperiod, and match light intensity to the specific plant types and tank size to prevent algae growth and support healthy plant development.
2. Balance Nutrient Dosing
Follow a consistent fertilizer routine, such as the lean dosing method using Masterline Lean or ADA Fertilizers which are nirate free, avoid overdosing nutrients especially in low-tech setups and regularly test nitrate and phosphate levels to maintain a balanced and healthy aquarium environment.
3. Ensure Stable CO₂ Level
Use a reliable CO₂ system in planted tanks, maintain CO₂ levels around 20–30 ppm in high-tech setups, and run CO₂ one hour before the lights turn on and turn it off after the photoperiod to ensure optimal plant growth and stability.
4. Improve Water Flow & Filtration
Use efficient filters, such as aquael, shiruba, fzone canister filters for 60P tanks and above, position outflow pipes or lily pipes to ensure even water circulation, and avoid creating dead zones where waste and algae can accumulate.
5. Perform Regular Water Changes
Change 30–50% of the water weekly, use a gravel vacuum to remove debris and organic waste, and clean filter media according to schedule without overcleaning to preserve beneficial bacteria and maintain a healthy aquarium ecosystem.
6. Aquarium-Safe Treatments & Algaecides
When natural methods and cleaning don’t fully solve the outbreak, aquarium-safe algae treatments can help. Use them sparingly and only as directed.
• Liquid Carbon (Glutaraldehyde-based products) is a popular aquarium additive that serves a dual purpose, it provides a source of carbon for plants and acts as a good algaecide.
• Cyano Rid is an aquarium-safe cyanobacteria remover formulated to eliminate blue-green algae without harming fish, plants, or beneficial bacteria when used as directed.
• ADA Phyton Git Sol can be used to treat hair algae, when spot-dosed directly on the affected areas, it weakens and kills the strands over time.
6. Plant Heavily, Especially with Fast Growers
Include fast-growing plants like Hygrophila, Limnophila, and Rotala to outcompete algae for nutrients, and gradually introduce slow-growing species once the tank has stabilized to maintain a balanced and healthy planted setup.
7. Trim and Clean Regularly
Trim dead leaves and excess growth to prevent decay, clean algae from glass, hardscape, and equipment on a weekly basis, and use tools like chihiros algae scrapers or chihiros hard brush for precise spot-cleaning to keep the aquarium looking healthy and well-maintained.
8. Introduce Algae-Eating Livestock
Add algae eaters such as Amano shrimp, Otocinclus, Siamese algae eaters, or nerite snails based on your tank’s size and compatibility, keeping in mind that they assist with light algae control but are not a substitute for proper aquarium maintenance and balanced practices.
9. Be Patient & Let the Tank Mature
In new tanks, some algae growth is normal during the cycling phase, so it’s important to stay consistent with maintenance and allow the tank to stabilize naturally over time for a healthy, balanced ecosystem.