How to make a lvl 10 oasis

I'm just gonna Make do with lvl 9's if I find a lvl 10 its great but I'll make do

Level 10 oasis I have gotten twice but I don't know how I got it when I attacked it was level 9 after attack It showed up as level 10 so guess you won't see it turn into one. just luck I guess

I would like to see a level 10 oasis because a lot of the people on my server claim there needs to be a level 20 for level 10 oasis to start appearing.. I myself am not sure >.>

you dont need a lvl 20 in order to create a lvl 10 oases

and heres a link

viewtopic.php?f=1&t=9256