I just wanted to say thank you to the posters who experimented with the alternative rolls from Steve/preconfilter. Based on the feedback here I ordered four rolls, and have been very happy with the results.
The Clarisea rolls were always bunching up in the center, which eventually that caused them to narrow near the waste roll and let water pass by, essentially bypassing the filter and causing the unit to stop working.
These rolls work way better! I am nearly finished my first one, and it hasn’t bunched up at all. I am finally happy with my SK-5000 after months of frustration.
It seems that these rolls last about twice as long, so I suspect the micron rating isn’t the same. But my water is clear, detritus is getting removed, and the tank looks great, so who cares!
Thanks again to this awesome community.