Algae, the Annoying Organism

Green dust algae on glass

Algae is a tiny organism that grows in every aquarium, pond, lake, and ocean. It’s part of the aquatic habitat because it help lower nitrates. A little of it can help. But when you see it invading every part of your aquarium, it’s not going to be very enjoyable. Algae can come in many forms from thin hairy strands to slimy goo. It can give an unpleasant look to your aquarium.

How to Prevent it

There are many causes to algae. One is nitrates, not nitrites. Too much nitrates cause algae. Water changes help lower nitrates. Learn what nitrates are here and how to do water changes here. Another cause is too much lighting. In a planted aquarium with a good plant mass, lighting is absorbed from the plants and preventing the algae from getting any. But with a low plant mass or no plants, lighting is mostly left for the algae to grow causing problems. Another cause is too much nutrients. If you dose nutrients or fertilizers for plants, sometimes this can happen.  It’s true that plants take in the nutrients, but when you dose too much, the leftovers gets used up for algae and causes an algae mess. Too much co2 can also cause algae. As I mentioned before, keeping nutrients, co2, and lighting balanced is key for a planted aquarium. Co2 can lower some species of algae. But if co2 is too much and not balanced with the light, algae grows. That’s why keeping your co2 stable is important. Overfeeding fish food is a great producer of algae. A fish’s stomach is as big as their eye so don’t try overfeeding. The first thing overfeeding does is increasing the amount of waste fish make. Too much fish waste has nutrients for plants but also algae. That means you have to do water changes more often to prevent the algae. Also, the leftover food not eaten by fish is used for nutrients for the algae to take up and grow. Overfeeding does NOT help. Keep in mind to not place your aquarium in direct sunlight since the light is a great source of algae.

Black beard algae invading a plant leaf

How to Get Rid of it

Let’s say you forgot to read my “How to Prevent it” and already have a algae mess from making a few mistakes. One way to get rid of it is by manually removing it. That means scraping it off yourself. Some algae can grow on the glass of aquariums. Using an algae scraper, glass scrubber, or a “Mr.Clean Magic Eraser” can get rid of the algae on the glass. Another way is hydrogen peroxide or h202. Use only 3 percent h202, NOT 30 percent. It’s not dangerous because after an hour, the h202 dissolves into hydrogen and oxygen. Keep the filter on but remove your biological filter media or bio rings (learn more here) since hydrogen peroxide can kill the beneficial bacteria. After an hour, put back the biological filter media. There’s several methods for h202. One is spot treating. Add 4 ml on the effected area with a syringe. Do this to every effected area. If algae invaded your whole aquarium, a whole tank treatment is good. First, like always, remove the bio media. Then, add as much water flow in your aquarium as you can. Use a power head, a device which attaches to the aquarium glass and spins giving water flow from one side to the other. Use a powerful one over 500 gph. Water from the filter can make some water movement but not enough. Then add 20 ml per 10 gallons with a syringe. Wait one hour and put the bio media back in. It’s okay if you see dissolving bubbles coming from algae. Keep doing this every day until the algae looks dead. Then, do a 25 to 50 percent water change to get rid of leftover algae bits. Another method of getting rid of algae is “Seachem Flourish Excel.” These are generally used to add co2 for the plants but in a liquid form. Overdosing it 2 to 4 times the amount it says to dose gets rid of algae. DO NOT use this IF you have vallisneria, riccia, and some mosses. Some scaleless fish are sensitive to this too like shrimp, cory catfish, or loaches. You can spot treat it or do a whole tank treatment (2 to 4 times like I said). Then do a 25 to 50 percent water change to get rid of dead algae. Algae eaters help too. Siamese algae eaters or SAE, are great for eating black brush algae. Otocinclus are small and good for small tanks 20 gallons and under. Chinese algae eaters are ok but not the greatest algae eater since they aren’t very active. Pleco or plecostomus are pretty good at eating algae but make a big amount of waste. Shrimp are also great for dealing with algae but beware that some fish like cichlids like to eat them. American flagfish are also great for green hair algae but they’re pretty rare. Blackouts works too. Algae can’t survive without light so, a 3-4 day blackout works. A black trash bag should be wrapped around the aquarium where no light can come in. The bad thing is oxygen for the fish is decreased during the blackout. A simple air pump will help pump oxygen into the water. Plants will be okay too.  Read my other post to learn more about species of algae and how to get rid of them.

Siamese algae eater