Dam stuff
I've now had to clean my strainer out 4 times in 4 weeks. Totaly blocked with algae every time. I emptied tank after first time & rinsed it out best I could. It always happens to me in winter but never had it as bad as this before!!!
My theory is that it growes in summer and sticks to the internal surfaces of the tank, then this prolonged sub-zero weather kills it off so it comes unstuck & floats about in the water.
Could do with a pre-filter for the strainer that connects between 1/2" hose.