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. Phytoplankton happens to be key for your saltwater tanks looking at the fact that in the end the filter feeding invertebrates such as the clams, corals and sponges will get to eat on them 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. These are the Nannochloropsis, Isochrysis, and Tetraselmis. And in all of these strains of the phytoplankton strains that you can culture in the home for the saltwater aquariums, one that is seen to be the most popular is the 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. 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 that you need to note is that when it comes to the need to culture and grow your own, it will take you some investment in time and energy for you to set up the culture station and have the phytoplankton strain 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. To escape all these kinds of inconveniences with the growth of your phytoplankton on your own, you can make use of the available commercial products and use them to dose your saltwater aquariums with the phytoplankton strain of your choice.
Note the fact that many aquarists do dose phytoplankton into their aquariums as a supplement to the feeding schedule given the fact that they happen to be so natural and nutritious food sources for marine life.