Backflush with treated water, same way you do a hiker's filter.
Yes, I thought of that. With that filter being so exposed during dormancy, I would be afraid that the filter would get dirty on both sides (inflow and outflow), which would make backflushing ineffective.
I dunno. I guess I feel that just getting the container without the filter, then a separate good-quality
sealed water filter would be much more cost effective.