Blagdon makes pond equipment, and the Blagdon range at PeekAPaw covers the three jobs that keep a garden pond clear: moving the water, filtering it, and dealing with the single-celled algae that turn it green.
Start from the problem you actually have. Green water is algae suspended through the water column, and no amount of filter media will strain it out — that is what a UV clarifier is for. UV light binds the algae into clumps large enough for a filter to catch, which means a UVC only does its job with a pump and filter running alongside it. The Minipond UVC is a compact 9 watt unit that works with any in-pond or external filter; the Pro UVC starts at 18W for larger volumes. Treat the lamp as a consumable: Blagdon's own guidance is to replace it annually, because a lamp that still lights can have lost most of its UV output.
The Amphibious IQ is the pump end of the system, with a digital motor, motor-jam and run-dry protection, soft start and adjustable flow. The Clean Pond Machine is a foam-free pressurised filter with a UV clarifier built in, and its transformers, lamps, O-rings and filter pods are stocked as separate spares.
