Three year old pool getting lumps under the liner.

My three year old in-ground liner pool is getting horizontal lumps underneath the liner. I'm concerned that it may be rust. I'm hoping that it is the foam padding between the liner and the pool wall bunching up, but the lumps seem pretty hard and the foam padding hasn't slipped down from the top.

Any liner pool guys out there with the 411 on my 911?

I'm gonna ask our liner guy, Waste aka Ted. If anybody has any idea about this, it would be him.

Welcome to the Pool Forum!

Thank you Watermom, this really has me concerned. I forgot to mention, In these areas, I've had ground water bubbles between the liner and the wall.

Also My pool is a 16X32 in-ground
Salt water pool.

Yo, Gfresh - welcome to The Forum!

With high ground or 'surface water issues - I'm gonna double down and say that it is the wall foam. (I'm assuming that we are talking about the walls of the pool)

With a 3 year old pool and a liner that hasn't been chemically abused, you could easily fix this... it would require draining most of the water to do so.

It's getting late for me, so I'll leave it at this and await a response.

Ted,

The pool guy came out today. He pulled the liner out from the coping and stuck his hand down behind the foam padding and pulled out a white slime he claimed to be
calcium. He said that it was nothing to worry about, and it would come and go with ground water infiltration. Any thoughts on these findings would be appreciated.

Thanks,
George

Thanks for getting back to us.

I'm leery that it's calcium, though I can't quite put my finger on why. If it's not the wall foam (and the wall foam would be secure at the top, it's floating up the wall from the bottom! *) then I'd be more inclined to say that it is oxidation from salt.

* If he was able to reach his hand behind the foam from the top, the foam isn't very well secured! (and if it's that easy to reach behind at the top, it's worse at the bottom, where water can rise behind it!!)

I don't know the topography of your pool location, but I'm assuming your pool sits in either a hollow or on the down slope of a hill. Probably, the best fix would be to install a curtain drain to divert the excess water away from the pool. Another option is to install a well point and sump pump. (if they hit water when they built the pool, they may have installed a well point)

If I knew more about you pool and where it sits, I could advise better.