Green water algae blooms
Green water algae, caused by a bloom of free-floating algae, can turn your aquarium into a cloudy green mess.
Green water algae in aquariums is primarily caused by unicellular phytoplankton, such as species from the genera Chlorella and Scenedesmus. These microscopic algae remain suspended in the water column, giving it a cloudy, green appearance.
These organisms are notoriously resilient, and once they’re in your aquarium they can be very frustrating to control. Any method you use is going to take at least 1 week to really show results, and many others take much longer.
It’s important to stay persistent- it will clear up!
One of the most effective ways to treat this problem is by using a UV sterilizer. This device passes water through a chamber where ultraviolet light destroys algae cells, progressively clearing aquarium over the course of one to two weeks.
Using a UV Sterilizer to Treat Green Water
Choose the Right Size: Ensure the UV sterilizer is appropriately sized for your tank volume.
Proper Installation: Position the sterilizer in your filtration system or connect it inline for efficient water flow.
Run Continuously: Operate the UV sterilizer 24/7 until the water clears, which usually takes a few days to a week.
Monitor Water Clarity: Once the water is clear, you can reduce UV use to occasional maintenance.
Husbandry Tips to Prevent Green Water Blooms
Limit Lighting: Reduce the photoperiod to 6–8 hours per day when you’re home and avoid placing the tank near windows.
Control Nutrients: Perform regular water changes (20% weekly) to keep nitrate and phosphate levels low.
Avoid Overfeeding: Feed 1-3 times per day, only what your fish can consume in 2–3 minutes to prevent excess waste.
Maintain Filtration: Clean filters regularly to ensure proper water circulation and debris removal.
Add Live Plants: Fast-growing plants can outcompete algae for nutrients.
By combining the power of a UV sterilizer with good habitat maintenance practices, you can keep green water algae at bay and enjoy a crystal-clear aquarium year-round.
