To open the options, look for the wrench button at the top right.
That will bring up the settings window. Select Global Filter from the left hand side.
The Global Filter allows you to hide unwanted tweets or filter out tweets in order to find a specific person or tweet or just keep them out of site while working.
All you need to do is write in the people, words, or sources you want filtered in the appropriate field separated by commas. It will immediately update your feeds. Example, if I filter Facebook as a source.
Deleting or clearing the field brings your updates right back!
That’s all the Global Filter settings, go back to the Settings list to find the other sections!