Algae is a too-common problem in planted aquariums, causing hobbyists to throw their hands up in frustration and often dismantle tanks that are otherwise perfectly good. Despite your best efforts at setup, sometimes algae will find its way into your tank Ė but donít give up. Here are some tips for dealing with the creeping green (or brown) menace.
1. Overplant your aquarium
When it really comes down to it, an alga is just another plant. Providing an environment where your plants will thrive also creates an environment where algae has the potential to get a foothold. However, if your plants are aggressively out-competing the algae for nutrients, it will swiftly die off and new surges of algae activity will be kept to a minimum. To be successful with this technique requires careful monitoring and frequent water changes, so get your chemistry set ready.
2. Stock algae-loving animals
Algae-loving animals should really be a part of any planted tank, but for some setups this is much more challenging than others. For example, if you have a Cichlid species tank, just tossing in some Otocinclus catfish, Nerite snails and Amano shrimp probably wonít help since your fish may eat your algae-hunters. However, Mollies and Platties may be able to fit the bill in these tanks and their aggressive breeding habits wonít be an issue.
3. Increase circulation
If your algae problems seem to be more localized, you may have a circulation problem. Just because youíve gone to the trouble to provide everything your plants need to thrive, it doesnít mean they can get it if itís pooling away from them. Increased circulation moves water more aggressively, mixing everything in the tank to create a more homogeneous environment. When circulation is increased, those little pockets of algae may simply disappear. Any tank can benefit from an added spray bar to help stir things up.
4. Lower the lights
Bright lights are an invitation for algae. Itís a tightrope walk to keep enough light for your plants to thrive without providing so much that algae gets encouraged to grow without limit. Choose dimmer bulbs or put your lighting on a timer and switch it off after about 10 hours. Your plants will be happy with this amount of light and algae growth will slow dramatically. If your tank is in a room with ample ambient light, take that into consideration when choosing new aquarium bulbs Ė after all, bright room lighting or light from a nearby window can encourage algae growth, too.
5. Inject CO2
Light and carbon dioxide, otherwise known as CO2 to aquarium hobbyists, are among the most important elements in photosynthesis. If the plants in your tank arenít getting enough CO2, they canít use up the nutrients in the aquarium and continue to keep the algae at bay. There are plenty of plans online for homemade CO2 injection systems for smaller tanks, or you can purchase a commercial CO2 system for your plants. Commercial systems have the advantage of allowing you to set them and forget them, but homemade systems are less expensive. Both are effective tools in the war against algae.
6. Fertilize your plants
It may seem counter-intuitive, but fertilizing your plants is a really good way to keep algae killed back. With adequate light and CO2 in the water, your plants still may not grow aggressively enough to crowd out algae stands. Adding fertilizer, especially nitrogen and micronutrients like iron, can give your plants the boost they need.
Phosphates from excessive feeding have been implicated in algae outbreaks, so apply it with caution. When your plants are healthy and growing well, theyíll use up most of the CO2 in the system, as well as those nutrients youíre providing, to create a low-algae environment. Make sure to test your water often when applying nitrogen fertilizers to protect your fish from overexposure.
7. Accept it
Last, but not least, remember that the presence of algae is a part of the planted tank environment. Thereís no way around it Ė you canít keep every tiny molecule of algae away forever. If thereís a light dusting of algae on rocks and an occasional bit on the glass, clean them regularly and accept it as a win.
Algae thrives under the same conditions as your plants, so as long as you have plants, youíll have some algae. The goal is to keep it under control, because trying to eliminate it all will just drive you out of your mind. If you simply canít bear algae, but love the look of a planted tank, consider some of the high-quality plant replicas available in the aquarium trade today.
Algae can be a real menace to aquarium keepers, but if you understand what this microscopic plant community needs to thrive and take pains to manipulate your environment away from those conditions, youíll find itís easy to keep in check. A small amount of algae can add some interest to a planted tank, though, so experiment with control methods until you find the one thatís right for your environment.