Phytoplankton are basically the microscopic plant-like organisms, photosynthetic creatures that drift about in the ocean and absorb the sunlight turning it into delicious sugars. Looking at their essence in your saltwater tank, the filter feeding invertebrates such as the sponges, corals and clams will finally feed on the phytoplankton for their nutrition. Phytoplankton have been billed a good source of nutrition for your marine life looking at the fact that they have a generally high level of concentration in Omega 3 unsaturated fatty acids which happens to be one of the key nutritional needs in a number of the invertebrates.
You will basically have three most common strains of the phytoplankton that you will be able to culture at home for your saltwater tanks. By and large, these are the strains such as the Nannochloropsis, Isochrysis and the Tetraselmis. Looking at all these strains, the one that happens to be most common and popular is Nannochloropsis. The Nannochloropsis strain of the phytoplankton is seen as being one that is so well balanced in the phytoplankton strains as they have rather relatively higher levels of the fatty acids, HUFAs and EPA, which happen to be quite essential for the growth of the larval fishes. Thus if at all you are looking forward at breeding saltwater fish, Nannochloropsis is the phytoplankton strain that you may be well advised to start with. Further to this is the fact that Nannochloropsis has as well been seen to have some antibacterial properties in it.
When it comes to the need to culture or not to culture phytoplankton, the choice will generally be your own to make, looking at the pros and cons. The reality however is that growing your own phytoplankton will be a bit of an investment in time and energy as it takes some time for you to set up your culture station and to have them grow. Over and above this is the fact that after you will have so set up the culture station, in as much as the strains mentioned above are as hardy and will go, you will need to spare some time for maintenance and monitoring of the set up on a daily basis or else the culture may crash. Instead of going through all the stress there comes with culturing your own strains of phytoplankton for your need to dose your saltwater aquarium, you can alternatively settle for the many available commercial products for the same purpose and avoid all the inconveniences there may be with the option of culturing your own.
Bear in mind the fact that many of the informed aquarists actually do dose phytoplankton into their aquariums as a supplement to their feeding schedule all due to the fact that they happen to be such natural and nutritious food sources.