i just started my tank 2 weeks ago, and i agree with mixing lr. i got 15# from my uncle that i used as base rock. he says it's figi, but not very good looking and some is very dense(alot of water displacment).i ordered 60# of not fully cured figi lr for 2.25 a #, and i plan on getting some tonga branch and shelf within days. figi is a more dense rock in my opion, so a more porous rock is ideal but i wanted a good solid foundation to build off.