On 9/6/13 7:08 AM, Markjump wrote:

Thanks a lot for above two responses.

Yes, it is perhaps the case: the water is very hard and has full of
high mineral content....that will be OK if there is no harm for people
living with me.

However, why David E. Ross loves bricks with different amounts of
minerals? Are you an artist? Can you find anything beautifull from the
picture I attached?


No, I'm not an artist.

The flower pot in the photo looks okay. It appears that the plant is
well established and not newly planted. The pot also looks unique, not
like a million other pots fresh from the nursery.

When reusing an old pot, I do remove the mineral crusts that form on it.
Leaves resting on those crusts are sometimes damaged by the minerals.
In my area, the crusts can also be too salty for many plants. But I do
leave the stains left behind when the crusts are removed.

If the stains bother you, try wiping them with a rag soaked with vinegar.

--
David E. Ross
Climate: California Mediterranean, see
http://www.rossde.com/garden/climate.html
Gardening diary at http://www.rossde.com/garden/diary