These pipes are protruding out the side of a pool deck near a spa/hot tub. What is their purpose?
Did someone steal the pool pump?
Vent stack for the spa blower.
Is that a guess or knowledge?
They definately appear to be vent stack pipes. They allow the jet pump to suck in air into the spa return and increase the water speed (air moves easier than water.) To verify, turn on the spa motor and you should hear air sucking in these pipes. Cupping your hands over them while running should stop the bubbling effect inthe spa and pool seat jets.
Excellent way to verify. Also I would probably recommend a screen on the intakes.
Thanks. One did have a screen.
Knowledge, otherwise I wouldn’t have taken the time to reply.
Also, likely to be a suction relief vent in that mix.