2nd Spring for this pond being full. Water is quite clear. What is this brown fuzzy mess that is attached to every hard surface in the pond? I noticed some a month or so ago but it just keeps growing... how do I clean it up... pretty sure no one is going to be wanting to swim, if it gets worse.

Tilapia go in on Saturday and I'm in the process of installing aeration.

To me the brown fussy looks like a form of filamentous algae (FA) that is coated with very fine silt-clay that is contributing to the majority of what is making your water cloudy. From a distance the algae looks link one of the branched types of FA maybe Stigeoclonium.

Here's the picture:

Never seen that