Hi all,
If they are Limestone rocks unless I am mistaken you are going to have a very hard water tank.
its very old limestone and does not have a huge effect on water parameters.
They <"
are limestone">, and they will have some effect on water hardness, but it will be relatively small, because they are old (Carboniferous age about 320,000,000 years old) and very hard.
We have <"
rock of that age"> in Ireland, around Bristol, S. Wales, White Peak, Pennines and as a ring of rock around the Lake District.
Where the limestone is exposed, <"
as "limestone pavement">, you get micro-solution features (from the rain) called "karren". This has allowed people to age <"
Neolithic portal dolmens etc">, where the orientation of the cap rock has changed from its orientation in situ.
In Ireland, where it rains a lot, you can get peat bogs form directly on top of the limestone, because the rain is leaching away the bases more quickly than they are coming into solution. A few years ago I used to go to the Carron Turlough (in County Clare) where there is a magnificent <"
limestone heath">, with transition from peat bog to bare limestone over about 30cm distance.
cheers Darrel