The water that comes from my tap is usually 7.8. not sure why. what i would like to have is around 6.0-6.5. without adding any chemicals. i will be adding 3 "large" pieces of mopani and 3 "large" pieces of malaysian wood. will this do it? tank will be 112 gallons. fish a 6 severums. also, i know there is a price difference(here anyway), but which is actually better, the mopani or malaysian? and what really is the difference?? P.S sorry for asking so many "newbie" questions but you guys give the best,all around answers on the net!