I tried the barley straw this past spring after I got filmilgous algae, and it really seemed to help. They say that there is several ways to do it,but I just put about 5 30# bales around shore line of my 1/2 acrer pond,with about 6" exposed. They tell me I should put straw in before the algae starts. So this spring I'm going to put it around shore at last week of March. We"ll now more after this trial this spring. One thing I did do was drive the plastic rebar into each bale to hold in place, then this fall I removed the bales and will install new this spring. Only had to pay 1.50 bale from some amish family that grows it here.( No expert here just willing to try different things.)
P.S. Some farmers here tell me they have thrown in hay bales in their ponds to make them more clear.