Phytoplankton fertiliser F/2

Perhaps the best known and most commonly used fertiliser for cultivating marine phytoplankton is the liquid phytoplankton fertiliser F/2. It goes back to the F fertiliser developed by Guillard & Ryther in 1962, although the original concentration of the formula was subsequently divided in half. This explains the name F/2. This fertiliser is suitable for the cultivation of most marine phytoplankton species.

3 respectively 4 components - why?

Our fertiliser is largely based on the F/2 fertiliser according to Guillard, however, some modifications have been made which have proved successful for us in daily practice:

• The main components of the F/2 fertiliser (nutrients, trace elements and vitamins) have been distributed over three individual solutions in order to significantly reduce the risk of contamination or the occurrence of precipitation. For you, this results in a significantly longer shelf life and usability.
• In addition, the silicate contained in the original formulation is available as an extra solution and can be added only when needed, depending on the phytoplankton species to be cultivated. This way, when feeding the mature phytoplankton, no unwanted silicate enters your reef tank. In general, silicate is only needed for the cultivation of diatoms (e.g. Rhodomonas sp.). You can order the silicate component separately in the shop.

Application and dosage of phytoplankton fertiliser

We ourselves successfully cultivate all the micro algae we offer on this fertiliser.

To prepare the finished culture medium, add 1 ml of each of the three fertiliser solutions to 1 litre of fresh (preferably previously sterilised) seawater. If you want to cultivate diatoms in the medium you have prepared, you must then add 1 ml of our silicate solution. The recommended dosage of 1 ml of the respective fertiliser components per litre is to be understood as a guideline, which works for the cultivation of most phytoplankton species, but may have to be reduced or increased (depending on the phytoplankton species to be cultivated).

How quickly the fertiliser is consumed depends primarily on the setup of your culture (culture tank used, lighting intensity / duration, strength of aeration, additional use of CO2, etc.) as well as on the amount and type of phytoplankton used for inoculation.

We recommend starting with a phytoplankton:medium ratio of at least 1:5. I.e. if you have a culture tank with a volume of 5 litres, you need 1 litre of phytoplankton as starter culture and 4 litres of medium. In general, the more phytoplankton you use for your culture, the lower the risk of contamination with bacteria or other phytoplankton species.

You should generally only feed phytoplankton that no longer contains fertiliser. Otherwise there is a risk that unwanted heavy metals/trace elements will get into your aquarium and cause damage to your reef inhabitants or lead to unwanted algae and bacteria growth.

You can determine whether your culture is ready for harvesting by measuring the nitrate. A ready-to-harvest batch no longer contains nitrate, which in turn means that the fertiliser it contains has been completely used up (only applies to the special phytoplankton fertilisers!). Nitrate test strips suitable for marine water or normal drip tests are suitable for the measurement.

Storage

Store the vitamin solution in a dark and cool place (refrigerator).