Streaming API v1.1: Try to get only Tweets with Hashtag


I am using the Streaming API v1.1. In my programm I would like to count hashtags. But most of the tweets, the Streaming API send, don’t contain a hashtag. Is it possible to filter the stream, that I only get Tweets with hashtags?

I tried using this URL:
The %23 corresponds to # ( But it still doesn’t work.

It would be great to get any help or tips!

Best regards!