Al, very little is really known about the barley straw.

An interesting couple of posts from a year or 2 back mentioned the effect on red algae. Texas and other areas have had quite a few fish kills in ponds and large lakes due to the red algae. Possum Kingdom Lake on the Brazos lake chain has been absolutely devastated by the stuff.

The guy that posted had a large ranch pond/lake somewhere around Wichita Falls Texas. All private ponds in the area had been clobbered. He tried barley straw and was the only one in the area that had no red algae. He credited it to the barley straw.

It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.

Without a sense of urgency, Nothing ever gets done.

Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP