Hello -- I think I have mustard algae.

[rkovelman]

Will do! Figured that something cheap would be a guess.

Anyone order from these guys: http://www.vminnovations.com ?

[PoolDoc]

Yes, they are one of the sellers on Amazon. VMI and Amato are the 2 most common. There've been a few complaints about both, with Amato doing a bit better than VMI, but as far as I can tell, they'll both make things right eventually.

For a while, Amazon was selling the K2006C directly, and that was preferable, but currently both the K2006a and the K2006c seem to be available only through 3rd parties.