I recently decided I've had enough with my aquascape, I bought 2 marco pedestal rocks to replace some existing rock with. I put the first pedestal in my sump for 3 weeks, I then pulled the biggest structure out. Using a 3lb hammer I broke the structure up into manageable pieces (I used e-marco to bond all of the rock work together). The pedestal was put into the display and some of the bigger pieces I broke up were put into the display as well to not disrupt the system. Fast forward I added my second pedestal rock to the sump over a week ago, when can I move that to the display and pull 2 more pieces of rock out? I do run a fair share of pond matrix and even added some more in preparation for the moves. I'll admit, I haven't tested the water at all. I've also not noticed any side effects to what I've done so far. The rocks on the left will be replaced with the new pedestal.