Green water and sludge that builds up in your pond will often leave it looking unslighty, and not at all like the perfect water feature original designed. Green string algae, cloudy green water or sludge build up will all start to effect the water quality over time as well, so getting it broken down and treated will make a big difference to your pond, and any inhabitants in it as well.
This is an easy to use fizzing tablet, available in a 3 or 10 tablet pack. Each one tablet will treat 500 litres of water, and can reduce the required maintainence as well. These are so easy to use, they can be simply dropped directly into the water, at the required dosing rate. These effervscent tablets will then slowly break down to disperse the active ingredients around the pond.
Ideally, place these near to a good water flow, to ensure it is spread evenly across the pond. If required, repeat doses can be completed weekly for the first month, and then monthly from then on.