Algae Bloom in Aquariums: How Long Does It Last?

Aquarium water is filled with microorganisms, and some will go through a blooming period at some points. For example, bacterial bloom happens when you first stock a newly established or cycled tank with plants or fish, and it can last up to three days. The water turns very cloudy, but this signals an abundant colonization of Nitrobacter, which will help you keep the ecosystem healthy and balanced. There’s another visible bloom that results from the rapid reproduction of other microorganisms, specifically phytoplankton spores, which are commonly known as green algae. This bloom often happens overnight and when you least expect it. It may last three days if you leave it be, but it could last even longer when it returns.

Understanding Green Water Algae Bloom

You can always count on phytoplankton being present in just about any aquarium that holds tropical fish. Even though there’s a higher likelihood of green water episodes in freshwater tanks, they can even happen in a koi pond. A freshwater aquarium would need higher levels of phytoplankton in its ecosystem, at least when compared to a pond. With this being said, a green algae bloom is a signal of the water being saturated with excess nutrients, and it’s a situation you want to avoid. Remember—light plus nutrients equal algae!

What Algae Bloom Looks Like

Unlike bacterial bloom, green algae won’t turn the water as cloudy. However, you’ll know it’s taking place because of its neon-green aspect, which almost looks psychedelic. You won’t see algae forming on the tank walls, substrate, decorations, or plant surfaces. Those are different algae species. When the volume of green algae particles increases, the water will switch from bright green to an appearance that resembles pea soup.

The Dangers of Green Algae Bloom

Let’s say you have an established freshwater tank to which you add two new fish. If the water turns green after a few hours, there’s a good chance additional and mature spores hitched a ride with the fish. You can do a 25 percent water change, turn off the lights, and wait a couple of days for the bloom to come to an end. It’s unlikely for toxins to be released at this point. Once the tank resembles pea soup that resists 50 percent water changes, there would be a risk of toxicity and increase ammonia levels. Again, turn off the lights and keep indirect light away from the aquarium as well.

Dealing with Algae Bloom

Algae needs light and nutrients to bloom. If the tank is getting too many hours of direct sunshine, you may want to block the sunlight or relocate the tank unless you can commit to more frequent water changes. What’s more important to determine is the possibility that you may be overfeeding your species. In some cases, algae bloom will happen before the water test kit indicates ammonia levels on the rise. Planted tanks are less likely to develop algae bloom, and you can also introduce species such as shrimp and Asian algae eaters to help you control algae growth.

Whether you need a product to control algae or any other fish tank supplies, you can find what you’re looking for at Aquatic Warehouse. We’re located in Kearny Mesa, or you can order anything you need from our website and have it shipped to you. Have any questions? Feel free to give us a call at 858-467-9297.