Thanks. Yeah, I'm pretty fuzzy on most chemistry too. Some things like the effect of (too much) algal growth seem counter-intuitive to me at first. After all, plants make oxygen, right? But other steps kick in and decomposition ends up lowering the DO.
I sort of assumed that barley straw would be the carbon (food) source for the microbes that would also be using up O2 to eat it. Apparently not a big part of the equation.
I had no that hydrogen peroxide inhibits algae growth. I'll look into that discussion here with interest.
My hunch about the (re)cycling of nutrients in a pond was barely touched on in the article -- "Some reports determined that barley straw might also act as a clarifier by flocculating fine particles in water." If some biological activity is helping settle out resources from the water column, maybe they are less available to algal growth? I dunno. How stable/unavailable nutrients become in sediments and how desirable that is probably depends on a lot of factors including local conditions.
Thanks for the discussion! I look forward to digging into many threads here. It seems like a nifty community with a lot of talents and enthusiasm for high-quality h20.
