Yes, but you'll need to add it slowly over time, not all at once. If you can, keep it cured in some type of container. Only take a small amount out and add (if parameters are right) like you mentioned, that shouldn't cause a cycle. Also adding a small amount over time will ensure your critters won't get buried under the new sand. It's not a quick method, but nothing in SW is (if you want to do it right). HTH