hello all. So im upgrading my 90g reef tank to 180g. The person im buying the tank from is giving me his sand also which is in the tank. Now how should i do the upgrade. Ive read that the best way to do it is to rinse his sand with ro di water then mix it with mine and add bacteria bloom. Or should i just buy new sand for 180g? im planning on using my 90g plus 50g water. Is there anything i should do to make the transition smoother????