Thanks to many helps from people here, I got new starter which seems to be going well until now.
What I have done and am doing is like this; around 75 ~80% of hydration, putting the culture in the fridge during daytime and taking it out at night . I fed it twice on day 1 and 2 .
Many recipes say 'once a day or twice a day' , but I'd like to know the condition of culture at the time when the culture is ready for the next feeding .
Is this the time when the culture has collapsed back to it's original size ? Or just should I wait for 24 hours or 12 hours as the recipes said ? Isn't there a possibility to mess up all the job because the culture is fed when it is over developed or prematured ? I am a little bit concerned about this problem as I couldn't follow a standard recipe .