Packs of barley straw are being used to control overgrown algae in the duck pond at Brodie Castle.
National Trust for Scotland (NTS) officials are employing the technique to prevent the risk of the build-up deoxygenating the water and endangering the wildlife at the popular spot.
The organisation has said the type of algae present is not “directly harmful to wildlife” and SEPA tests showed the water quality was “acceptable”.
However, efforts to rot the algae using the barley straw are not quite hitting the spot.
An NTS spokesman said: “We have in the past been able to remove the algae by using barley straw and we are currently trying this technique again, albeit with limited success so far.
“The cause is an increase of nutrients in the water stream that feeds the pond – most likely as a result of run-off from farmland due to current spreading.
“The only danger to wildlife comes if the build-up of algae is such that it deoxygenates the water and we are actively working to avoid that.”