From my understanding you should transport all live rock submerged in water or you risk killing of the bacteria that will then require curing. If you put a lot of LR
that has been out of water for a while in a tank it can cause spikes in your ammonia levels, if it's just a small piece and you have a large established tank then the spike may not be significant enough to cause any problems. If you want to play it safe you could cure it in a temp tank/ bucket...
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