Before I get to the question, some back ground. I bought a house in December with a pool that had been neglected fairly badly. My first pool. I managed through a lot of work - and a lot of help from folks here - to finally get the water sparkling, clean and perfect early this month.
My neighbor's colossal Live Oak trees (the worst tree God ever plagued pool owners with) have been the main challenge. They just got through a three week period of dumping about 10 large yard bags a week worth of leaves. Now they are dropping those pollen things ("oak worms"). After a windy Sunday night, they filled my entire yard 2'' deep. I see no concrete or grass - just oak pollen. Overnight. I've never seen anything like it. Thank the Lord we are not allergic to it.
Anyway, my pool turned cloudy and green in one night from the pollen. I know it's the pollen because FC is steady around 5.0. So I decided it might be a good idea to backwash the filter to prepare it for the onslaught. But then I looked at the gauge.
I backwashed about 3 weeks ago when the needle on the gauge was close to the red marker (around 29 bar). There's a green marker around 16-17, so I figure the needle ought to stay between the two. After I backwashed 3 weeks ago, the pressure read 10 bar - far below the green level. I decided not to worry about it as the water looked clean and I knew I had added the proper amount of replacement DE (6.0 lbs for a 7.5 lb filter).
So now, 3 weeks later, the pressure is still around 10 bar. Is something wrong? As I said, prior to the pollen invasion, the water was sparkling clear, so it seems to have been working, but 3 weeks is a long time with no change, especially since I did an algae shock and a lot of leaves fell in.