Secondary filter

[BigDave]

I like the idea, cleaning mode / polishing mode. You'd just have to be sure to size the new filter for the flow and pressure you require.

[waterbear]

Simpler solution, why not just get some celluose filter aid such as Fiber Clear, Purifiber or ZeoFiber and add it to your cartride when you want to 'polish' the water. It will do it's job until you hose it off the cart and will not have much negative impact on mean time between cleanings.

[BigDave]

Does the fiber stuff really work? I used Fiber Clear in my sand filter last year and it didn't seem to help much. When I opened the filter to winterize, I found large grey lumps on/in the sand bed that looked like a paper delivered to my driveway in a rainstorm then run over. It wasn't covering the sand bed but in big lumps. I had bachwashed and rinsed prior to opening the filter.

[kelemvor]

Simpler solution, why not just get some cellulose filter aid such as Fiber Clear, Purifiber or ZeoFiber and add it to your cartridge when you want to 'polish' the water. It will do it's job until you hose it off the cart and will not have much negative impact on mean time between cleanings.

I had considered it, but saw a few recent posts where folks suggested not adding things like this to a cartridge filter. Perhaps that was for actual DE only, because all the alternative products I see have instructions for use in cartridge systems. I figure worst case I ruin a filter and have to spend $80 on a replacement. It's going to be time for a new filter soon anyway as mine is about 18 months old soo...

I took your advice and went and got some "Jack's Magic Filter Fiber stuff" which as best as I can tell is the same thing as zeofiber, purifiber. More importantly it's what the pool store had, and it was cheap ($6 for 18oz). The instructions indicated I'd need about 16oz to get the 1lb pressure rise on a 125sf filter, so I mixed about 3/4 of the bag in a bucket and added half of that. Checked the pressure and it was already up 2 pounds. I sealed the bucket, hopefully the slurry will keep for a few days.

I'm going to run the pump overnight, that should get me several turnovers with the fiber in there. It's already been running a few hours, probably close to long enough for a turnover (just kind of a guess though since I don't know the pertinent numbers to calculate it). I can't really see any difference yet.