It depends on what cycling method you are using. If you have livestock in the tank, then you need to do water changes to mitigate the effects of ammonia/nitrite on the critters. If you are using the fishless method, I wouldn't do a water change until all traces of nitrite are gone. Uncured LR
has some things on it that are going to die. This contributes to the cycling process as it decomposes. What you don't want to do is add uncured LR
to the tank after it cycles and you have fish/inverts in there. The die off from the rock will cause a mini cycle and could harm the tank inhabitants.