Renew the barleystraw minibale you put into the pond last February/March. It is getting old now and you need to add its replacement to the water alongside it to keep up a constant inhibiting factor to combat greenwater and blanketweed algae.
Leave the old minibale in whilst the new one is activating but make a note to remove the old one next month.
It will do your pond no good at all if a barleystraw minibale is left to rot down completely in your pond as that will add to the rotting compost heap at the base of your pond.
Continue to add Extract of barleystraw weekly to a small pond or container pond feature to keep the water free from greenwater and blanketweed growth in these summer months.