Is my MTurk task too long?

I am a first-time requester via MTurk. I have recently created a survey-based HIT that will take 30 minutes to complete. It is limited to US participants aged over 18 years, and the remuneration is $10. I am looking for quality responses, so I followed the guidelines suggested and limited the HIT to workers with a rating over 97% and 10,000 assignments. The task has been open for around 7 hours and I have had 1 response. Is this normal?