Demi:

I agree with you. Russ and Laura are very considerate in allowing us to recomment other products while using their forum.
I keep kosher or vegan, when I can't find kosher certified products.
I use Nordic Naturals Algin. They state that:
All Nordic Naturals products are doctor recommended, pharmaceutical grade, molecularly distilled, and third party tested to document the absence of all environmental pollutants (No PCBs, dioxins, pesticides or heavy metals).
The best price I have found ($19.99 for 120 veggie caps) is
at www.healthcare21.com.