How do folks backwash?

[PoolDoc]

Looked at some old drawings; I'm fairly sure that's not really a back-washable filter. It's no longer made, so I can't find a manual, but I would imagine the service guys just opened it, and a port or drain at the bottom, and washed it down.

DE powder is find in garden soil; you just don't want it blowing around and getting into your lungs.

[SL Dan]

There's a whole rig on bottom where, in one position it's normal and the other it says backwash.

Can I add a few images?

[PoolDoc]

Sorry; can't help.

I've never been around that filter, and didn't see a manual online.

[SL Dan]

This is what I have:

https://www.manualslib.com/manual/12...te%20SM%202036

[PoolDoc]

Looks like that manual is only partially readable? And, I assume you do NOT have the associated separation tank?

Still, with my limited experience with residential pressure DE filters (most of the DE filters I've worked with were giant commercial vacuum DE filters), it's worthwhile to periodically break down the filter. Unlike sand filters, backwashing DE filters only seems to work partially. Full cleaning requires opening the filter, ESPECIALLY if you haven't done so in a while.

[SL Dan]

I've done it 4 or 5 times so far this year. And right, I don't have the separation tank. Until I DL'ed that manual, I didn't even realize there was a separation tank. This filter was gotten by our last pool man.

But I'm wondering what most people who have DE filters do with waste water/DE/algae when they backwash.

[PoolDoc]

It sounds like you are looking for a discussion on the topic; there's probably enough traffic on TroubleFreePool for a discussion. Not sure about PoolSpaForum. You may want to register and post your ? on TFP.

[PoolDoc]

• All filters function better with low flow rates per sft of filter area. This is ESPECIALLY true with sand filters.
• All filters run longer between cleaning with low flow rates.
• High flow rates tend to damage filters. High flow = high differential pressure which KILLS filter cartridges, especially modern 'high-capacity' cartridges with pleats that are too close together. High flow may damage DE membrane support grids. High flow WASHES SAND OUT of the filter during backwash, and PUSHES DIRT THROUGH the filter during operation on sand filters.
• It is still possible to develop high differential pressure, across the media, with oversize filters but it's much less likely.

Is that enough? If you need more, you'll have to wait till later this weekend.

By the way, REGARDLESS of filter type or size, you need a WORKING pressure gauge to monitor filter ops properly.

• NO FILTER should operate at over 30 psi absolute (unless it's the new-ish Pentair high-pressure sand filter).
• NO FILTER should operate at more than a 7 or 8 psi pressure rise (clean to dirty). Cartridge filters should be cleaned at a 5 psi rise (old style) or 3 psi rise (new style with pleats too close).