New Build Calcium Nodules

[mstymndy]

Hey there.

So our pool was plastered at the end of June. In the last 2 weeks we noticed calcium nodules on the plaster, mainly along one wall that are just getting bigger. We called the pool company and they sent someone to scrape them off, but researching it and talking to my pool technician, it sounds like it may be indicative of a bigger problem? The pool company is saying that it's water intrusion from behind the plaster off the gunite that is perfectly normal and that using sc-1000 will help balance it, but everything I read online says that its a deficiency in the plaster itself. Thoughts?? I'm not sure how I should proceed. I have no desire of replastering my entire pool, but I also don't want to just live with it if there is something actually wrong with the plaster.

 

[mknauss]

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

Some information on them.

 

[mstymndy]

Hey there.

I was directed to this thread educating about calcium nodules which I've been researching quite a bit lately. So our pool was plastered at the end of June. In the last 2 weeks we noticed calcium nodules on the plaster, mainly along one wall that are just getting bigger. We called the pool company and they sent someone to scrape them off, but researching it and talking to my pool technician, it sounds like it may be indicative of a bigger problem? The pool company is saying that it's water intrusion from behind the plaster off the gunite that is perfectly normal and that using sc-1000 will help balance it, but everything I read online says that its a deficiency in the plaster itself. Thoughts?? I'm not sure how I should proceed. I have no desire of replastering my entire pool, but I also don't want to just live with it if there is something actually wrong with the plaster.

 

[onBalance]

Please post two or three photos of the calcium nodules. Let's make sure that the problem really is calcium nodules.

 

[mstymndy]

They're still relatively small (small pea sized) so hard to take pics of underwater... especially with an iPhone when it's bright, but this is what I've got. There's about 20 of them though.

 

[onBalance]

Ok, that does look like two small calcium nodules. However, why is there a very large white discoloration outer ring from the small nodule? To help me, perhaps two photos from a little further away?

 

[mstymndy]

it's just the light shining through the water.

 

[onBalance]

Okay, thanks for clarifying.
What the pool company told you is wrong. But since the nodules are very small, there is a good chance that scraping or sanding them off may resolve the problem. Get the company to acknowledge the problem in writing, and then allow them to remove by scraping or sanding without draining. Wait a few months and see if more nodules form again. If nodules return, IMO, they should re-plaster the entire pool.