Talking of phytoplankton, these are basically microscopic plant-like organisms which are photosynthetic creatures that drift about in the ocean absorbing the sunlight and turning it into delicious sugars. They are essential for your saltwater tank for the fact that the filter feeding invertebrates such as the sponges, clams and corals will feed on them for their nutrition needs. By far and large, phytoplankton happen to be seen as a good source of nutrition for marine life for the fact that they have been seen to be high in concentration of the Omega-3 unsaturated fatty acids which is a sure dietary need for many 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. This is the particular phytoplankton strain that is largely seen to be the best for the fact that it happens to be well balanced, having such better levels of concentration of the essential fatty acids, HUFAs and EPA, which are more than essential for the growth of the fishes at their larval stage of development. 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. Over and above this, Nannochloropsis has as well been deemed to be a good fit for saltwater aquariums for the fact that it has some antibacterial properties.
By and large, the choice will be yours to make as to whether you will be culturing your own phytoplankton or not. But all in all you need to appreciate the fact that it actually takes some time and a sure investment for you to get to set up your culture station and as well prep the stuff to 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.