Live vs. Concentrated Microalgae Feed

Algal Concentrates

Concentrated microalgae is a shelf stable option for people who want the nutrition but at a cheaper price. This version is usually centrifuged, so algal cell concentrations increase, meaning more food for your larvae. In addition, algae concentrate is convenient, with no risk as the algae cells are usually heat sterilized. This makes it the go to for many mariculture hatcheries as a way to prevent introduction of contaminating bacteria, making it so a $50,000 tank worth of larvae don't die to bad sterility techniques. As the cells undergo heat processing, they "leak" causing nutrients and oils to spill out, which can improve appetite. However, concentrates should not be used to feed copepods, as they need live algae to promote a feeding response. They can cause ammonia spikes and potentially flocculate, potentially causing toxicity.

Live Algae

Live algae is the often times preferred way to feed filter feeders due to their nutritional nature. They are living, meaning that copepods have a better feeding response to it. Furthermore, the live algae can absorb excess nutrients like nitrates in the water column, which is beneficial. They are the premium choice for serious cultivators who want to culture extremely sensitive bivalve larvae or copepods in the early stages of life. Unfortunately, the logistics of shipping and cultivating live microalgae is a major downside. Live phytoplankton are a sterility issue, meaning they might be secretly contaminated with bacteria despite the cultivator's best efforts. Moreover, maintaining live culture is expensive, with specific aeration, nutrient, light, PH, and more variables. Get one wrong and your entire batch can be wiped out, leaving starving marine life.

www.sciencedirect.com/science/article/abs/pii/S0044848616307797 Accessed 01 May 2026.