Question about DE filter

[Poconos]

I would imaging something the size of oregano would be caught with or without the DE in the system. Don't know what kind of valve you have on the filter but if you inspected the grid, fingers, or whatever they're called in the filter, then I would suspect water is bypassing the filter at the valve. Maybe a multi-port? If it is one of these then there is an internal gasket that could be messed up. Any more info on the valve? Model etc?
Al

[Jlwine]

I hadn't thought of that. That is an interesting idea. It is a mulitiport: Filter-Rinse-Backwash-Recirculate-Waste-Closed I don't know the brand off hand--I'll check tonight.

The part that confuses me is that the water is other wise crystal clear--all other signs would appears that the filter works just fine. I took it apart last night and examined the grids--no problems at all. However, only the top two third of the filter were covered with DE. I cleaned everything and added more DE this time. Nevertheless I am with you that even without DE at all you would think particles that big would be filtered. That is why your multiport suggestion is interesting.

[mshumack]

You didn't say have size or brand DE filter you have but usually you put in 1 lb of DE powder for every 10sq-ft of filter area. For example a 60 sq-ft filter takes 6 lbs of DE. It sounds like your not adding enough to cover the grids.
Good Luck

[Jlwine]

It is 24sq feet Pentair FNS plus. I have one of those 44 fluid once cups you get from a fast food joint. I had been using three cups, last night I put in five.