Want to upgrade from one external to another, any help on how to do this guys? Obviously i wouldnt just take one out and put one in, due to losing beneficial bacteria.. Should i soak new external media in tank water, then swap? Should i run them both for sometime, then disconnect old one? I know if two filters run, then take one away, i will lose half my beneficial bacteria.. But will the beneficial bacteria multiply quick enough to cover the contents and size of my tank? Or will it break down, not multiply and i have to cycle again? What ya reckon?