Eric did his in a mountain brook as I recall- crystal clear water, no suspended solids whatsoever.
Show us your results! I'm very curious what you experience.
You'll have to wait till March, when I come back from my hollydays, to see my under-the-sea photos. But I'll show you my sink attemps soon! (I'll begin as soon as I finish with my exams and as soon as I finish the camera).
Thanks you all for the support!!