Macroalgae, or sometimes so called seaweed, seems to have become within the last years more and more popular amongst marine aquarium hobbyists.

Previously macroalgae were often used specifically to provide a natural way to export the nutrients in the aquarium water, which means that the algae will grow by using compounds like nitrate, phosphate, ammonium and some heavy metals in the tank water.

During this photosynthesis process, it uses carbon dioxide too and turns this into additional oxygen for the aquarium inhabitants.

As well it will help to raise the pH level in the tank and increase the tank carbonate buffer capacity, which means a more stable alkalinity level.

In addition, it is often used to provide additional hiding spaces for copepods and rotifers.

Nowadays thanks to the variety of available macroalgae species, macroalgae can still fulfil these very important functions but they add a very important benefit too . . .

. . . a beautiful and more natural looking tank.





Very important is the right choice of macroalgae species.

As there are invasive and non-invasive algae species available, it is recommended to get all

the information you need about the macroalgae in mind before adding it to your marine tank.

No one wants to have the nightmare to realise that they have chosen the wrong macroalgae for their tank after it overgrows the whole tank or the corals, right?!

Our aim is to provide you all the information you need to choose the right macroalgae for your tank and to get all the information you need to keep them successfully in your own marine aquarium.

You might wonder why we actually recommend having macro algae in the tank, while so many people seem to try to get rid of algae in their tank using chemical or mechanical nitrate and phosphate remover, to reach a phosphate/nitrate level of 0.

Well, the truth lies in the difference.

Microalgae on the one side, like phytoplankton, provide an important food base in the open sea.

They are mostly one-cell algae species.

Especially microalgae species like diatoms (Bacillariophyta), green hair algae (Chlorophyta) and the dinoflagellates (Dinophyta) are the most problematic microalgae you will come across in the marine tank hobby, as they can become a serious problem in the tank.

So-called Macroalgae on the other side, are easily explained algae which you can see with your naked eye and contain mostly many cells.

The various macroalgae species can enrich the whole tank by:

Ability to suppress unwanted microalgae, like green hair algae etc.

Reducing the nitrate and phosphate level in the marine aquarium

Providing shelter for small fishes, copepods and rotifers

Natural food source for critters and fishes to keep them happy and healthy especially Tang fishes need a good portion of daily algae to stay fit and healthy

More natural look of the marine aquarium to enjoy

BTW: Algae is already the plural for these marine plants, and in singular, it is called Alga :)