Frozen is fine, but it's the live stuff that I find completely unnecessary and not worth the risks. If you read about the results people get in the testimonial section at nlpublish.com (the website for New Life Spectrum) you will see how the best pelleted foods are superior. Even the president of the American Cichlid Association wrote a personal letter explaining how he got colors out of cichlids using NLS that he could not get with ANY other diet.