Jim of Ohio said this "This was a great buy, and I could not be more pleased. The pack had visible amphipods of all sizes, and I didn't even find one that had died during transit. That I could even make out a few copepods, told me there were hundreds more. If you follow the directions for introduction into your tank and you have lots of places for the pods to hide in, you'll find they distribute themselves quickly. I would definitely order again - my Mandarin couldn't be more pleased as well."