16.2.2. Algae in High Tech Tanks

Photo of author

Author : David Bogert

Published :

The translation of this article has not yet begun. There are still open tasks such as converting units or creating tables.

We define a “high tech planted aquarium” as a planted tank with carbon dioxide injection and high intensity lighting with some crimson and blue light.

There are a whole list of things needed for the good growth of higher plants in the high tech planted aquarium:

  • One plant every three inches across the whole aquarium
  • The proper amount of carbon dioxide or CO₂ (15 to 30 ppm)
  • The proper amount of light (with blue and crimson included in the light)
  • Proper Temperature 76 to 79°F, 24 to 26°C
  • Decent water circulation ONLY low in the tank
  • Fertilization
    • The proper amount of nitrogen (ammonia, nitrite, or nitrate)
    • The proper amount of potassium
    • The proper amount of phosphorus (preferably at the roots)
    • The proper amount of iron (preferably at the roots)

Algae control in high tech planted aquariums is surprisingly simple IF you take the advice of Dr. Tom Barr (His excellent blog is “The Barr report“, a site now largely edited by the very knowledgeable Jason King). Dr. Barr recommends something called the “Estimative Index” or “EI” method of fertilization. He recommends adding an overload of fertilizer which takes the fertilization variables out of the mix and greatly simplifies preventing algae. Dr. Barr also recommends a very high loading of potassium fertilizer.

Dr. Barr also recommends ONLY heavy planting of any high tech planted aquarium and a temperature of 76 to 79°F, 24 to 26°C.  So if you take Dr. Barr’s advice (which I highly recommend one does, this guy knows his stuff!), the only variables left are CO₂ and lighting. Probably 80% of the problems with algae in a heavily planted high tech planted aquarium can be solved just by varying the carbon dioxide level.

High Tech Planted Aquarium
High Tech Planted Aquarium

When starting out in a high tech planted aquarium only use light levels of light, fertilizer and CO₂. Then increase all these variables as the plants grow. This will typically avoid problems with algae. One can illustrate this best with a chart:

A Balanced Aquarium Fertilizing Program
A Balanced Aquarium Fertilizing Program

Now this chart is only a very rough guideline. Some plants grow very fast and this timeline can be moved up. Other plants take forever to grow and the timeline has to be extended. And some plants do just fine with high CO₂ right from the start. Some plants do not do well that way. And occasionally you will get a species of algae that just loves the EI method of fertilization (something called “green spot algae” are one algae that loves the EI method). Go figure!


Plants vary considerably in their temperature requirements but few plants do well with temperatures over 80°F. Blue green algae is a bacteria. Bacteria love high temperatures. An outbreak of blue green algae (cyanobacteria) almost always occurs in aquariums over 80°F. But then blackbeard algae loves lower temperatures. The ideal temperature for plants and fish seems to be about 76 to 79°F, 24 to 26°C.  For a more in depth discussion of temperature go to this link:

4.2. Aquarium Temperatures

More Information on Controlling Algae

There is a lot more information on how to control algae in these links:

16.2. Controlling Algae in the Aquarium

16.2.1. Controlling Algae in the Fish Only Aquarium

16.2.3. Controlling Algae in the “Low-Tech” Planted Aquarium

16.2.4. Algae Eaters

16.2.5. The Algae “War”

16.2.6. Chemical Control of Aquarium Algae