So I researched this a little more and found this on the Wyeast website:
Originally Posted by Wyeast Website
Harvesting yeast from the top of open fermenters (top cropping) is still a widely used practice in the modern brewing industry. Specific yeast strains which rise to form a dense head must be used, making top cropping nearly exclusive to ale and wheat strains. As with other methods of harvesting yeast, harvesting a consistent population which avoids the extremes is important.
Yeast should be harvested once fermentables have been reduced by 50% or more. The timing of the skim should be consistent from batch to batch to help maintain fermentation profile. A head will rise approximately 24-36 hours into fermentation. The first “dirt” skim containing trub should be discarded as should the final skim. The middle skim should be harvested and used.
This morning I skimmed the Krausen a second time and the foam bubbles were much finer and slurry like. Because of the first skim, the trub was gone. I went right down to the the level of beer. I feel good about it this time.
I'm going to make a starter with this on Thursday or Friday and brew up another batch on Sunday.