Cures for bad Flying stars

[myfs_96300]

Hello Cecil,
I would like to have a little precision please.
When you have to cure a sector (bad flying stars)is it enough to put just one object or do you have to put a lot of.
For example you need to cure the east part of your house with water; Is just a painting scene at this part is enough.
What about the plant I have at this place?
Do I have to put it in another place ?
Many thanks for your kind reply.