Bees Swarming Algae Residue

[johnssc1]

Does anyone else have this issue?

I have been alternating cartridge filters, filtering out dead algae, and after 24 hours, I have a decent amount (>10) of honeybees eagerly cleaning off the grey gunk that the hose missed

Maybe it is fermenting back to sugars?

 

[Bama Rambler]

I haven't seen it but knowing bees, it doesn't surprise me.

 

[257WbyMag]

Interesting. A pic of this would be interesting to see.