Bill -- your question about scientific studies gave me an idea. I looked for citations on "barley straw" in one of our available search programs (Fish and Fisheries Worldwide). It only came up with two references. I've posted them below, and neither one really looks like it will have much of interest?? Perhaps that Aquaculture paper might have some literature review?? I certainly have no experience with any of this.
ANON
Control of algae with straw Part I. Koi
SA: South African Koi Keepers Society Newsletter, Issue No.117, pp. 1-4; 1999
COOPER, J.A.; PILLINGER, J.M.; RIDGE, I.
Barley straw inhibits growth of some aquatic saprolegniaceous fungi. Aquaculture, Vol.156(1,2), pp. 157-163; 1997
Dave
