Is it
Poop
Algae
Detritus Worms
Bio Film/Calcium Crust
Mulm
Humidity loving flies
For me, it's Mulm. When it builds up it goes in and under everything and piles up quick. The slightest movement makes it fly everywhere. You can't even siphon the stuff good.
Crusty calcium that sticks to the glass, lids, filters, and top frame. Sometimes white, sometimes kinda yellow.
Those pesky flies from moisture in the summer months.
Poop
Algae
Detritus Worms
Bio Film/Calcium Crust
Mulm
Humidity loving flies
For me, it's Mulm. When it builds up it goes in and under everything and piles up quick. The slightest movement makes it fly everywhere. You can't even siphon the stuff good.
Crusty calcium that sticks to the glass, lids, filters, and top frame. Sometimes white, sometimes kinda yellow.
Those pesky flies from moisture in the summer months.