pH of Lava Rock?

[Nicky]

Does anyone know if 'Lava Rock' is suitable to be used in a planted tank? What pH does it has?
Ever tried attaching Java-moss to Lava-Rock? I saw one tank with Java-moss on Lava-Rock but the moss just will not stick.

[David]

hi nicky

i cannot remember about 'Lava Rocks'...as long as it is lime free, it will not affect your tank PH level,(but to be exact it is the KH and GH level).

If you like to attach Java-Moss to the rock, you need to use fishing line to tie the moss down till they have taken roots on the rock itself.

[Nicky]

David, what do I need to look out for in a 'lime-free' rock?
This lava-rock are basically brown porous rock (very low density).
How do you tell if it is pH >7 or <7 or neutral?

[David]

hi nicky

usually its those whitish rocks that is highly possible for having some sort of lime stuff in it(execpt for fossil wood....i think). the rock itself does not have any PH value...its what it leech or dissolved into the water that raises the KH thus the PH....Just like coral chips....in itself, it has no PH valve but as it 'dissolves' in the water, it rises the KH that ultimately raises the PH.

[kenny_G]

i had a lava rock the size slightly smaller then my fist tied with some moss. the moss according to the person who sold it to me, will grow better. the moss is growing well.

the kh in my tank is normally around 6-7 even after weekly water change. did not put in anything to rise it.

keb

[DEA]

lava rock no pH one
you're asking about the effect of lava rock on the pH of water?
i think it should be neutral