Phytoplankton Dosing & Storage

Phytoplankton is the basis of the marine food chain.  Reef keepers have reported excellent coral and invertebrate growth and maintenance by dosing with phytoplankton.

The volume of phytoplankton that you add to your reef tank depends on the nutritional demands of your system.  Consequently, you will need to experiment with your system to arrive at the optimum dose.  Guidelines have been published by a number of phytoplankton suppliers suggesting a dose of 5 ml per 10 gallons, 3-4 times per week.

Manual Dosing:

Phytoplankton can be dispersed in the water column or you can directly target feed specimens.  It is recommended that you turn off protein skimmers for 30-60 minutes after dosing phytoplankton.

Automated Dosing:

You can grow a phytoplankton culture using the PhytoTank with the Culture Cap and then use a PhytoTank with a Dosing Cap to maintain the culture for 7-10 days for automated dosing using a dosing pump.  One option is to use two PhytoTanks, one to grow a culture while a second PhytoTank is used for dosing the culture that you grew the previous week (retaining a small amount to use a starter culture each week).


Phytoplankton can be refrigerated for future dosing or culturing.  Experimental data suggests that phytoplankton can remain viable in the refrigerator for as long as 5 months (with weekly shaking to prevent settling).   However, in our hands, phytoplankton stored for more than 90 days is less effective as a starter culture.  If you use refrigerated phytoplankton as a starter culture, then you may observe a lag period before additional growth is observed.  This is particularly noticeable for isochrysis galbana wherein you may see the culture become significantly lighter in the first few days of culture and then it will gradually get darker.  This lag period is not observed if you start a new culture with fresh phytoplankton that has never been refrigerated.