Well, thanks to all you good folks on the introductions group, yesterday I ordered the pool testing kit and was marking time until delivery. Also yesterday I backwashed and rinsed the filter (didn't see much change in the glass viewer) and put the setting back to filter. However, today on returning from work I see the pool level has dropped. I'm thinking it could be to do with the backwash/filter/etc valve. I jiggled the valve about a little and fingers crossed it's okay now but clearly there is a problem with the valve too. I also used the Barracuda pool cleaner and found that the filter seemed ineffective - simply pumping the dirt back into the pool as if on re-circulation. So things aren't exactly going swimmingly here. Anyone have any suggestions? Attached are the pics.