At least 5 pages of about 400 words each ...

It varies for me day-to-day. Busy days it's 2-5k words, but most days it's a thousand or less

mine varies too.. microblogging..maybe almost 10-20plus posts a day.. emails, sms, papers.. too long to count.. some times way less

so in sum #1-4 pages.

being a grad student requires a lot of writing probably more for you as a doc candidate