database capacity? please help

Hi Everybody
Acutually we have implemented Transactional log backup every four hours a day,differential backup every eight hours a day and a full backup once per day plan in the server for the particular database.
After implementing this my database size is goes arround 60gb from 30gb within one day. After that I have shrinked the database.Then i got the old database size 30gb.now the database size is 30gb and space available is 1gb.
Is it advisable to have above plan?
The tool always showing full database capacity.
How come i can avoid full database capacity (i.e) redmark in database capacity monitoring tool .
Also suggest how can i avoid the dataloss from database.

please share your ideas.
Thanks in Advance
Vijay.s

Your data size is 30 GB , when reindex database you need extra about 30 GB, so at least 60 GB needed for database.
when you backup log file , the extra space is truncated, and re-used again.
It is better not to shrink database, shrinking may hurt performance .
if you want avoid increase of database due to reindexing , set sort_in_tempdb true , and increase the initial size of tempdb to be 40% of datbase data file.