Why Annual Clearing is Wrong - The Truth about Pad & Media Bag Filters

Why Annual Cleaning is Bad
The Truth About "Annual" Cleaning

Ponds and water features that only are cleaned once per year contain a year's worth of sludge consisting of detritus, mulm, decaying organics, and algae.
As organics decay, toxic hydrogen sulfide gas is released causing foul odors and harms fish gills.
Sludge is anaerobic (void of oxygen) which encourages harmful parasites and pathogens to proliferate.
Anaerobic conditions encourage harmful Aeromonas and Pseudomonas bacteria to proliferate.
Sludge is a breeding ground for Branchiura (Fish Lice), Lernaea (Anchor worm), Gyrodactylus (Skin fluke) and Dactylogyrus (Gill fluke) as well as harmful protozoa - Trichodina, Costia, Ichthyophthirius multifiliis (Ich, or White Spot), and Chilodonella .

Annual cleaning requires the catch and removal of all Koi and pond fish which raises their stress level, which lowers their immune systems.
Annual cleaning is a leading cause of Koi and pond fish disease and death.
Annual cleaned ponds and water features generate larger amounts of algae than systems routinely cleaned.