It looks like these filters have been out for 10 years, but there is surprisingly little information anywhere about them, including here. Instead of the laterals having slots, they're covered with some material to filter finer than the sand. Does this get clogged quickly by everything that gets through the sand or are they great and function similar to a normal sand filter but with better filtration? They laterals are way more expensive too - Pentair's catalog is ~$8 for a normal lateral and >$100 for a clearpro one.