Rotifers can be fed on a variety of “small micron” feeds and the resulting rotifers will have the nutritional profile of those feeds. There are several diets available for growing rotifers, but by far the best diets consist of marine microalgae. Marine microalgae contain the full spectrum of important nutritional components needed for larval development, including fatty acids (especially ARA, EPA, or DHA), sterols, carbohydrates, proteins, and vitamins. Microalgae produce almost no fouling in rotifer culture systems (unlike powders and emulsions) making it much easier to maintain long-term rotifers cultures.
The most commonly used algae for growing rotifers are Chlorella and Nannochloropsis, and they both will sustain high growth rates and healthy rotifers. However, Chlorella provides essentially no ARA, EPA and DHA. Nannochloropsis contains a high content of EPA, which some fish can convert to DHA. But many fish require a substantial DHA concentration in their feed, and for these fish rotifers must be “enriched” with other algae that are high in DHA. We have recently introduced a new feed called Roti-Grow Plus that has a Nannochloropsis base, but also contains a high level of DHA. This combination will produce high quantities of rotifers that are "enriched", providing the very best nutritional profile for your larval fish and corals.
The last 12-24 hours of feeding are the most important for determining the nutritional value of the rotifer. Even two hours of enrichment can provide substantial enrichment by “gut loading” the rotifer with the desired feed, but for optimal enrichment more time is needed in order for the enrichment to be incorporated into the rotifer tissues.