Even if the rock is cured, there will be die off during transport. This die off is minimal if you buy it from, for example, a lfs 20 minutes away from the house. But from a website with overnight shipping, you're going to get a lot of die off. So to answer your question, yes this is normal for online lr. In the future, when you get it, you should cure it in a rubbermaid tub with a powerhead for a while.