Calcium Nodules?

[PecanOrchardPool]

I read some of the threads on this topic and think this is what I have, but would love an experienced eye. I noticed three of these on my pool wall a few days ago. All three in the deep-end on the pool wall, near my wall tile grout lines. One of them was close enough to the surface that I tried to knock it off with the brush to see what it was, it looked white and crumbled. After that I started googling. I originally thought it was salt and then stumbled on calcium nodules and logged into TFP to learn more. The remaining two are still there and I haven't been brave enough to go into the water (66F) to see if there are holes in the lumps. I attached two pictures.

 

[ajw22]

They probably are calcium nodules which are a form of delamination. Nothing you can do about it until you replaster the pool with a full chipout.

Calcium Nodules in pools

What are calcium nodules? In swimming pools and spas, they are small mounds, bumps, deposits, or “slag” piles of calcium carbonate which are formed from material that has been released from the plaster. The small calcium nodules are rough to the touch, hard, and generally gritty. Nodules may...

www.troublefreepool.com

 

[JB007]

I had something similar on my pool' but is was on the back of my spa spillover, right at the grout lines. From advise here, I was able to pretty much solve the problem by re-grouting all around and on top of my spill over. its only been 5 months, but have not seen any built up yet. Guess i have to go thru the summer to see if that solved it.

 

[Jimrahbe]

POP,

Looks like nodules to me...

I suspect that JB had efference, which is different than what you have..

I have the same thing in a rent house pool.. You can sand then down, but they will just come back in a few months.

Thanks,

Jim R.