hey guys was a monster fish guy but have decided to give africans ago, i have a 5/2/2.5 tank and looking at stocking it with a few colonys including, frontosa, crimsons,hongi, yellows and loachs, was looking for some rocks to build some caves etc, i want to go to the landscape place and buy them as they seem to be alot more cheaper, i just dont realy know what are aquarium safe rocks there, if anyone can help that would be great, thanks