I am looking to go from my 55g to a 75 or 90, If i use all my rock for now and add some new sand would i have a problem with the cycle or would it be like a big water change? also would i have to fight diatoms all over again with the new sand? Does anyone know the best place to get a new tank because the scratches in my used 55 drive me crazy. I will use as much sand and water from the 55 as possible.
