Algae Explained

Algae is present in virtually every aquarium on the planet. Like all other plants algae needs light, heat, and a nutrient supply. In general terms algae do not compete with other plants as they have different nutritional needs than higher plants. In order to do well, they need ammonia to develop into the flagellate state from the spore state. Thus, they do not do well in an aquarium with favorable water conditions and plants that are growing well (plants are getting all of the nutrients they need, CO2, Macros potassium, nitrogen, phosphates, micronutrients, and organic matter in the aquarium is kept to a minimum). Contact me for nutrient levels for your specific setup. If water changes are not done on a frequent basis, (once a week in my opinion is best) and other conditions in the aquarium are deteriorating such as organic breakdowns producing ammonia, the ammonia levels will increase to levels that bring algae spores into the flagellate state. When plants don't get every nutrient they need, plants will go into a starvation mode and release ammonia through their leaves and or organic breakdown will produce ammonia and awaken the algae spores. Algae conditions are now favorable, and will multiply rapidly because these are the favorable conditions of algae. Because of their rapid growth rate, they rob the other plants of light and nutrients to the point where they cause further damage and eventually the plants die.
New aquarium setups are perfect for these conditions because the filter has not had time to be broken in and the normal breakdown of ammonia by bacteria does not yet occur. New aquarium setups need to be cycled with fish first so that ammonia is converted to nitrate by the newly growing bacteria before plants go in, if you give light and nutrients with ammonia levels you will get algae! New plants need a lag time to form roots and grow before they can produce oxygen and take up nutrients and ammonia to stabilize the new aquarium setup. Disturbing the aquarium substrate while replanting can stir up ammonia from the substrate and so planting should only be done at the end of the lighting photoperiod (twenty to thirty minutes before lights out) to lesson the chances of algae utilizing ammonia under the light to begin growing. The next section will now cover each specific algae and show why they are actually useful in solving existing problems in your aquarium.

Blue Green Algae

Blue green algae (actually a cynobacteria) is present as blue green, violet, or brown-black covering plants, rocks, and substrate. They particularly favor the substrate where water circulation is poor and ammonia is present. Other causes are that food and debris accumulate, oxygen levels are low, filters are poorly maintained or aquarium water is low in nitrate levels. I use my fingers in a new tank setup to remove the slime from the plant leaves, if you don't then your plants will literally suffocate to death, and suffer from lack of light due to the covering. Cure? Remove existing algae, make sure you have adequate nitrate levels, get your filter working properly to utilize ammonia feeding bacteria, do frequent water changes, and clean up excess debris with a siphon. There are no critters that will eat this form of algae. It can be killed with Erythromycin!

Red Algae

Red algae grows in beards or off color green threads on plants, rocks, or driftwood. They are difficult to remove and they will kill the leaves of the plants. They thrive in hard water with a PH over 7.0, and again, an ammonia content. Cure? Up your CO2 to acceptable levels, get nutrient levels to where they should be and concentrate on getting ammonia levels down with water changes and organic removal.

Diatoms (substrate or gravel algae)

Diatoms grow in a thin brown layer on rocks, driftwood and plants. Occurs in newly setup tanks due to silicates and ammonia as the filter and substrate have yet to mature. Cure? It can be vacuumed out or removed by hand. This usually disappears after a few weeks when the tank has matured. Otocinclus will remove some of it.

Green Algae

Light green floating algae more often than not is a result of overfeeding your fish. (most aquarists overfeed, take what you think your fish need in the palm of your hand and then cut that in half and that will be plenty) Other forms include the common glass algae. Cure? For green water a three day blackout of the tank (cover all so it is total darkness) with at least 40% water changes DAILY for those three days will generally take care of green water. Again, ammonia levels need to come down and water changes will help to do this. For glass algae a good old fashioned algae scraper will take care of it, and phosphate levels need to be adequate.

Green Thread Algae

Unfortunately, this algae actually occurs only when all conditions are RIGHT with an aquarium, namely clean, well fertilized water! So their presence is a good sign? Cure? Remove by hand being careful not to pull up the plants with them in the process. Florida Flag Fish love this algae and will keep your aquarium clear of it. (Florida Flag Fish get to be good size and are territorial and semi aggressive so do your research on them first before adding to a community tank)

Bottom Line? (For all algae)

KEEP AMMONIA LEVELS AT ZERO! How? By properly maintaining your filter (clean pads every other week in old aquarium water), frequent water changes (once a week, thirty to fifty percent), less food during feeding and more frequently for those who think their fish are not getting enough, giving plants all the nutrients they need, using proper lighting, carbon dioxide levels of 30 parts per million, using algae eating critters, cleaning suspended debris by removing it, and planting densely enough to begin with including some fast growing stem plants with newly set up aquariums.

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Faribault, MN 55021
Telephone: 507-331-5801
Fax: 507-384-3146

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