Too much DE in pool

[PoolDoc]

So . . . fix your filter.

[SL Dan]

If I could find what's wrong with it, it would have been fixed months ago. Are you saying that it will then filter the DE? That that's how I get it out of the pool?

[SL Dan]

I know that the filter has a leak - I've been looking for the source of it for about 3 years. But it's not any worse than it was, and this incident happened some time in March.

[PoolDoc]

I'm not talking about a water leak. DE will not pass through a functioning DE filter.

In fact, it won't even pass a functioning sand or cartridge filter ( though it can DAMAGE cartridges!). I've actually used that fact for years to test sand filters.

[SL Dan]

Ah, OK, thanks.

Well, I can take it apart again, the 3rd time, and see if I spy anything. But I'm pretty sure it would have turned up before.

[PoolDoc]

It's actually pretty straight forward:
+ You put DE in the skimmer.
+ DE shoots out of the returns.
+ Ergo, EITHER the piping is malfunctioning, and bypassing the filter
+ OR the piping is working AND the FILTER is malfunctioning.

DE does not pass THROUGH properly functioning DE filters.

Period.

But unless you REALLY know the filter . . . and how ALL the icky bits actually WORK . . . finding the bypass point can be a challenge.

[SL Dan]

Yeah, that's what I can't figure out. How could the piping be malfunctioning? It was laid underground almost 60 years ago; I've lived here for 25 years. How could it possibly be bypassing the filter (which is what it seems to be doing)?