The all natural pond treatment blanket weed remover clears blanket weed by depriving it of the nutrients it needs to thrive with a handy built in measuring chamber the dosage is easy to control and the product easy to use simply calculate the ponds volume l x w x d metres x 1000 pond volume in litres and gently squeeze the bottle until the required amount is in the measuring chamber 10ml is needed for every 250 litres 500ml bottle harmless to fish plants and wildlife when used as dir