Extra pipe?

[gregr]

Hi,

Looking for help ID'ing an extra pipe (new pool owner). I have an inground pool and can't figure out why I have 4 pvc pipes going into the ground near the filter. I don't have a connected vacuum system so I think my pool only needs 3 pipes.

2 pipes (with 1 valve) are returns from the skimmer and the drain -- the valve is set to 50/50 and feeds into the pump. There are another 2 pipes with a similar valve which also feed into the pump but the valve is "off." On this second valve, one of the ports is to the post-filter pool return. I have no clue what the other port (with pipe going into the ground) is for. Anyone have any ideas? Could it be for structural support or actually connected to something? There is a labelled photo attached.

Thanks,
Greg

[gregr]

Photo now attached.

[Denniswiseman]

I doubt if it's for structural support
Do you have a multiport valve if not it may be some way to simulate one, could the other pipe be going to waste

[gregr]

Thanks for the response. Here is another photo from a different angle with more of the plumbing shown -- hopefully this helps. I do have a separate multiport/waste line.

[Denniswiseman]

That's strange, why the return is connected to the suction side doesn't make sense unless it's for recirculating but that is normally done at the MPV
As for the other pipes unless they went somewhere else and have now been cut off

[gregr]

Thanks for looking. Is there a good way to figure this out?

[Denniswiseman]

If you don't see any other pipes elsewhere I would be inclined to leave well alone and just run it as it is

[gregr]

Thanks again. Running it is has been easy -- I'm hoping to start closing the pool myself and figure having a mystery pipe isn't a good way to start.