Buying a Neutral density filter?

Rite so after i had done my research on Neutral density filters. I went and bought a Neutral density 8 filter. Which allowed you a good space of time. I waited about a week as it was coming from china. Unfortunately i was stupid and bought a counterfeit filter.So after complaining i went to my local photography shop on post house whynd.I went and bought a neutral density 5- 6 and a neutral density 8-9. After buying these neutral density filters i went and experimented in my back garden as i did before the next post will be a series of test shots which i did to see the difference.