Rocks Malawi cichlids

Hi guys, what type of rock should i be using in my malawi tank(Haplochromis) to buffer the pH

 

Zainus, down at mnandi beach near you, you'll be able to pick up some stunning pieces of weathered rock, full of calcium to keep your water nice and hard and pH up. Down near the cliffs, just don't advise one to go alone.

 

thanks for the tip

 

Just watch out MCM arrested staff from one of the marine shops for collecting rocks/sand stone on Macassar beach for a clients tank...