I've spent a fair bit of time in the garden this week and have finally got around to vacuuming out some of the sludgy sediment from the pond. Initial efforts were somewhat thwarted by obstacles on the pond floor. Unfortunately, until the time is right to re-install the pump and underwater filter, the water lacks sufficient clarity to be able to see where such obstacles are situated.
As the pond vac restarted, following discharge of the previous cylinder load, I became puzzled as to why the suction wasn't working, as the motor was uttering its reassuring purr of strength. Having switched off the power, I duly removed the suction nozzle and sundry extension tubes but, all were clear. Next task was to disconnect the coiled suction hose from the cylinder where I observed a dark gelatinous mass at the top, almost as if a giant slug had taken up residence there. A vigorous shake of the hose revealed all, as a full grown frog, encased in mud, slowly unfolded itself. A few minutes later it took its first tentative hop back towards the pond.
I hadn't realized quite how strong the machines suction power was!
Today I donned arm length waterproof gloves and fished around to unearth some of these obstructive items, micromesh planters full of slimy aquatic compost but little sign of plant growth, planters full of oxygenating elodea and, old drainage pipes which serve as useful hidey holes for the ponds piscine inhabitants should predatory herons venture past the marginal reeds.
Obstacles removed I was able to use a freely sweeping action with the pond vacs nozzle, before restoring drainage pipe and elodea to their rightful place.