By sealing it i assume you mean to protect it?
You can maintain/recondition your granite tiles by using something called HCL89
What it does is that it cleans and reconditions your granite tiles and also helps to create a protection for it so that it always remains new.
You can usually get it from from http://hcl89.byethost10.com or http://hcl89.atwebpages.com
Hope this helps you out
If you want to DIY, you can use something called HCL89.to polish your marble by yourself
I usually get it from http://hcl89.byethost10.com or http://hcl89.atwebpages.com
What it does is that it polishes your polishes your marble and renews it (if its an old marble piece)
Hope this helps you out
Had same mould problem same as TS, so decided to purchase the HCL89 thing from http://hcl89.byethost10.com as recomended I used it about a month back and so far the mould seems to be gone Looks like it worked out well for me, thanks
You can use something called HCL89. Its strong enough to clean the mould as well as kill it I usually get it from http://hcl89.byethost10.com or http://hcl89.atwebpages.com One thing i like about it is that is creates like a protection like on my wall/tiles so that it prevents future mould or etc Hope this helps you out