where i live the water is quite soft, becuase i have being reading that guppies and the other livebearers like water hard, but i guess i could give it a try and see how the water's pH rises while the tank is cycling, also another reason why i want to use it is that i have some left that i did not put in my marine tank, so dont see the point in wastes it, if i can use to my advantage with setting up the new tank and that is why i was asking if it would be ok to use for a guppy/livebearer only setup.
thanks for the info drobbyb