DE vs cartridge filter

[sacredcow]

I never get algae blooms and keep hair nets on my skimmer to trap as much of the smaller stuff as possible. Consequently, I dismantle and fully clean my DE once a year, and usually don't have to backwash it (although this year I had to do one backwash due to it being very dry and dusty).

It's very YMMV, but helping friends with their cartridge filters makes me happy to stay with DE. I would 100% feel differently if I had to deal with one of the separators in areas where you can't discharge DE.

 

[bradgray]

I will say that the inability to backwash is a downer when fighting algae - I had to break down the filter and clean the cartridges weekly while fighting a nasty algae issue early this past summer.

Our experience is that sand filters are less ideal than cartridge when it comes to algae.

Yes, it's technically easier to "clean" the system when the flow chokes down but I'd argue you can't "clean" the sand filter as thoroughly as you can a fully removed cartridge.

On older neglected sand filters especially, algae - dead and alive - get left in nooks and crannies in sand filters. It's tough to purge it 100%. It's common for the sand to clump and for tunneling to occur on poorly maintained systems. It creates voids inside the medium where it's hard to technically get it all out without emptying the sand in the sand filter, which is a messy, obnoxious job.

Anecdotally, our green-to-clean recoveries also seem to happen faster on cartridge systems. It's more labor during the recovery, but we are definitely more confident we got it all.

We don't deal with algae on our regular clients homes, so the disclaimer is, this behavior may be the exception rather than rule. Those problematic sand filters were all recoveries that were not on regularly routed clients.