Hi, Karen - I haven't used Speedi-Beet myself, but I understand the beauty of it is that it is very quick-soaking. The website says 5 minutes in warm water, or less than 10 minutes in cold water.  The iron is a tad higher than average for beet pulp pellets, but not wildly so (one reason for rinsing beet pulp pellets before soaking is to remove iron and dirt). To me, it sounds like the bucket with the Speedi-Beet could be prepared, then by the time everyone else's buckets are prepared the Speedi-Beet bucket should be ready to go.

http://www.britishhorsefeeds.com/speedi_beet_typical_analysis.pdf

http://equi-analytical.com/interactive-common-feed-profile/