Inground pool is pitting..

[jwilliams]

I have an inground pool, refurbished by prior owner about 20 years ago. Walls are showing pitting, seems to be limited to first foot or two below the surface. Does this sound like a hardness problem ??

[PoolDoc]

May have been.

More likely, it was a pH problem. But, there are other things it could have been. I'd be interested in what was different about the plaster -- or water conditions -- in the affected area.

Note the past tense! If you have a concrete pool, you definitely need to manage your pH, alkalinity, and hardness . . . but doing so will only help prevent future problems, not correct present ones.

[jwilliams]

Pitting goes around entire perimeter of pool. 30k gal kidney shape. Filter runs 8 -10 hrs / day. I am guessing an imbalance in the water, change seems to have slowed since I have a better handle on water balance.

[PoolDoc]

Pitting goes around entire perimeter of pool. 30k gal kidney shape. Filter runs 8 -10 hrs / day.

Waterbear posted while your post was in moderation, where he couldn't see it. However, it's a worthwhile point: if you use floaters AND don't run your pump continuously, that might explain why the pitting is localized to the pool perimeter, rather than being uniform.

[CarlD]

I'm not the concrete pool guy but having been around here for a few years now, it seems that most hard-side pool owners need to have their hard-liner resurfaced about every 5 years. You've gone 20 so that's pretty good.

Carl

[PoolDoc]

Thread closed -- OP is an iPhone 'app developer' who spam-vertising his pool app for iPHones.

[waterbear]

I'd be interested in what was different about the plaster -- or water conditions -- in the affected area.

IF the pitting is localized on one or two areas of the pool my guess would be a floater or two tethered near the wall