Letter: Letters: Last straw

From JOHN ROBINSON

Irene Ridge’s letter (21 May) about the use of barley straw in pond
treatment raises again the question of the nature of the active ingredient.

For three successive years I have treated my pond with barley straw
at the recommended rate. For two years there was total success even after
a late start in the first year. In 1993 failure was total, blanket weed
even growing over the bales of straw.

This raises again the question as to whether the active constituent
is not, in fact, algicide or fungicide residues, and nothing inherent in
the straw.

John Robinson Macclesfield, Cheshire