I accidentally ran pump dry for about 15 hours. The pump is still “working,” but I realized something was wrong when my pool turned green. Cartridge filter: went to swap out with the clean one and only the bottom section was wet/dirty. Put the clean filter in and made sure water filled to the top and the pump primed. All was well. Vacuumed twice, brushed the surfaces, slammed with shock, no difference. Turned off pump and water sloshed out of skimmer basket/sputtered out of return. Opened the filter and still everything but the bottom section is dry. Any advice? I saw it could be a blown seal, but I don’t see anything leaking. Any advice would be much appreciated.