What's that plugging up my filters?

Use of lake or river water for irrigation can bring some unwanted visitors into your irrigation system. Small freshwater animals such as bryozoans grow rapidly inside pipes and are typical culprits in plugging of heads and filters. The bryozoan known as Plumatella vaihiriae is one of the most common troublemakers.

Often mistakenly identified as algae, seaweed or moss (which they somewhat resemble), bryozoans are common inhabitants of freshwater around the world. In fact, the word bryozoa translates from Latin into"moss…