Phytoplankton form the base of the food chain in marine waters. It refers to all free floating organisms that use light to synthesize food. Phytoplankton is critical for rearing larva, and is very useful for feeding a healthy reef tank.
Some corals are suspected of eating it directly, while others consume crustaceans (pods) that eat Phyto. Tridacna clams consume Phyto directly, and it's generally considered critical to their survival until they grow large enough to feed completely off of light (around 3").
Nannochloropsis (Nanno) and Isocrysis Galbana (Iso) are two species that are well known to marine researchers and have worked well for feeding aquariums. Nanno is a dark green, where Iso is more of a yellow color. They do have different nutritional profiles, but both are great for reef tanks.
These phytoplanktons may be fed directly to your tanks, with daily doses from a few oz per day per tank, up to 16oz per 100g (400ml per 378l) being used on high performing reef tanks. Start slow and work your way up as you dose.
Note that the added phytoplankton may completely consume available phosphate and nitrate, meaning you may need to dose them or feed more heavily to keep corals healthy.
Smaller clams (under 3") should be fed 2+ times a week, by targeted dosing upstream of the clam of 10ml.
BAS offers difference sizes of individually labeled containers of each species.
Note- This product is not normally shipped, due to the weight. If you are interested in a shipment, please contact us for a quote.
For further reading: https://saltyunderground.com/category/plankton-and-its-significance-for-your-aquarium