I have a 15g with currently a filter for up to 10g (That's what it came with ) I bought a new filter fit for 15g, same brand and takes same cartridges... Will I mess up everything accomplished in the past few weeks by switching filters even If I transfer everything from the old filter to the new one? Also, I'd rather not run both at the same time I want to put the old one in a different tank today. Answers much appreciated.