Good day to everyone here I sincerely apolgiese if this has been answered before or comes across as a silly question but I would really like an answer to this question any answers would be gratefully appreciated..so..I had a velvet outbreak and sadly lost all my fish apart from one which is now in QT..I've started my 76 day fallow period and am 5 weeks in..after the fallow period should I completely remove the sand bed and replace it with new sand or should I just leave the old sand in the tank!? I dont have live sand I have dry sand, would this benefit me in any sense or would it be a waste of time? Thank you for taking your time to read this I look forward to any answers.