Has anyone seen or dealt with this kind of algae before? It's very gelatinous, comes off the rocks easily, and creates bubbles when you disturb it. I'm trying to figure out what it is and how best to deal with it. It's in a 24000 gal pond built in 2016. Has a skimmer and bottom drain, aquadyne bead filter, under gravel perforated piping return and 6 return points around the perimeter. Also has 6 airstones around the perimeter. Any thoughts are greatly appreciated.