Originally Posted by Teammuir1
Will the cloud in a new tank harm the fish?
Not if it is normal. A new tanks have some cloudiness to the water, resulting from sand/gravel particles/dust (no matter how well you wash it), bacteria starting, and sometimes cloudiness in the tap water due to sediments, etc. None of this is harmful, and it should dissipate in a few days, sometimes longer. I have one type of regular gravel that even after 12 years still causes considerably more cludiness if I disturb it or move it, compared to my other natural gravel.