Every serious fish hobbyist knows the importance of keeping a healthy fish tank. However, new owners may struggle with their aquariums constantly turning green, which can be both frustrating and detrimental to fishes’ health. Usually, green-colored water is because of an algae bloom, and it’s necessary to identify what triggered this.
In this guide, we’ll look at all of the possible reasons why your home aquarium’s water keeps turning green.
Algae Blooms Can Cause Discolored Water
Sometimes keeping fish can seem like more trouble than it’s worth. Everything may seem like it’s running smoothly, but then the water turns from clear to green. This is often because of an explosion of a type of algae called phytoplankton. The population of this algae grows very quickly in a bloom. There are several reasons why this is a serious issue.
First, it’s unsightly because the water is a murky color, so you can’t enjoy your fish. The water may also emit an unpleasant odor. Meanwhile, when the algae dies, it depletes huge amounts of oxygen. Many inexperienced fish owners don’t realize that their pets need oxygen to survive. The fish will suffocate in the tank without it. Believe it or not, fish can drown!
Too Much Light Can Cause Algae Blooms
One of the main reasons why tanks suffer from green water or algae blooms is excessive light. Algae isn’t a plant, but it does possess the ability to photosynthesize. These microscopic creatures use sunlight to create their food, and this enables them to grow and prosper.
If you situate your fish tank in a window or bright conservatory, you may be giving it too much light. Consider moving it to another location, which may help ease the problem. Another issue is if you’re using artificial lighting. Try reducing the intensity to a lower setting if you notice sudden algae explosions. Hobbyists should aim for an eight to ten-hour light cycle. Use timers and be mindful of your plant and fish light requirements to keep a healthy environment.
Decomposing Food from Overfeeding Can Cause Green Water
Overfeeding fish is another common cause of green water in tanks. Many new fish owners inadvertently overfeed their stock, causing nitrate and phosphate levels to increase. They’re fodder for an algae bloom and one of the worst mistakes first-time aquarists make. Only give your fish enough food that they can eat in under two minutes.
Meanwhile, don’t forget to remove any leftovers as well as any dead plant matter. You should only feed your fish once or twice per day, depending on the species. Remember, overfeeding can lead to further health problems, including obesity, so it’s never a good idea!
Incorrect Cleaning Habits Can Affect Water Parameters
Poor husbandry is the chief cause of algae blooms or green water. Your tank won’t clean itself, so it’s important to stay on top of it. A couple of minor daily tasks will help to reduce your workload. Here are some tips:
- Remove any waste food or dead plants.
- Perform regular parameter checks using trusted water testing kits.
- Cycle 10 to 20 percent of the water every one to two weeks. This prevents pollutants from building up to toxic levels and harming your fish.
You should perform a deep clean of your aquarium once or twice per year or as needed. This can be stressful for the fish because you must transfer them to a backup tank, so don’t do it too often. Meanwhile, don’t forget to unclog your filter so it continues working efficiently. Why not add some bottom feeders, like pleco, to help maintain a healthy tank? Some of them will even eat algae. They can’t do it all alone, but they’ll make a big difference.
A Weak Filter Can Cause a Dirty Aquarium
A weak filter can result in green water. An effective filter should be able to cycle the water three to four times per hour. Anything below this leads to an increased risk of algae blooms and general tank problems. It’s critical to choose the right filter for your fish tank; some filters can be too powerful for smaller tanks and vice versa. They may affect the fishes’ ability to swim-– or even suck fry inside.
With routine maintenance, the filter should do its job properly. Don’t forget to clean it regularly to avoid clogs. The quality of even the best filters may degrade over time. We recommend keeping a backup filter if you have an older set-up.
Too Many Fish Can Make the Water Green
Overpopulated tanks are another common cause of algae blooms that cause green water. This is because the fish will produce too much waste in a congested space. All those nitrates transform the tank into a green nightmare. With too many fish, even a good filter may struggle to keep the environment clean. The general rule is that there should be one gallon of water per inch of fish. In short, a five-inch fish needs a five-gallon tank. Note: this can vary depending on the species.
Usually, a bigger tank is almost always better because it gives the fish more space to roam and hide. Dwarf seahorses and other nano species are a notable exception because they’re not powerful swimmers. The one-inch guideline doesn’t work as well with larger fish. For example, a smaller koi carp would need at least a 250-gallon tank to live happily. That’s why most people keep them in ponds instead.
Tip: Keep Live Plants
Aquatic plants add several benefits to fish tanks. They shield the water from receiving excess light and give the fish additional places to hide. Meanwhile, they consume the same nutrients as algae, so they help keep the water’s chemicals balanced. Algae can have many benefits in natural lakes and rivers in a balanced environment. Adding plants will prevent the algae from taking over and help replicate your fishes’ natural environment.
