Just what the title says. Right now it has sand mixed in with some crushed coral and some tufa rock(about 12 pieces). I will be stacking them up about 1/3 up the tank to make some caves. I got my p.h up to 8 but wil go up a little more when I get the rest of the tufa rock. I want some of the malawi, tanganyikan variety thats why I want the p.h that high. thanx yall.

