Calcium Nodules in pools

[pooldv]

Welcome to TFP!

Calcium scale presents as raised rough patches on the plaster and will be random across the pool. Generally, a scale line will show at the waterline on the tile first and if you have SWG the cell will scale and require regular cleaning. I have diligently maintained my CSI between -0.3 and 0 for five summers and haven't ever had to clean my SWG cell. If the CSI has been kept below +0.6, or even better under +0.3, then it isn't possible for the pool to scale. The SWG cell still might scale but scale won't build up on the plaster.

More about scale here, Pool School - Calcium Scaling

 

[oceanrider]

What about using Borates to remedy this problem?

 

[onBalance]

Adding Borates or Borax will have no effect on preventing or removing calcium nodules.
This is a bogus theory promoted by a plaster consultant as a way to suggest that calcium nodules are the result of improper water chemistry, and that adding or changing the chemistry will resolve the problem. Completely false.

 

[oceanrider]

Adding Borates or Borax will have no effect on preventing or removing calcium nodules.
This is a bogus theory promoted by a plaster consultant as a way to suggest that calcium nodules are the result of improper water chemistry, and that adding or changing the chemistry will resolve the problem. Completely false.

Sounds like their main goal is to shift the blame. As it is the plasterers who pay their way.

 

[dumbcluck]

The first 2 pictures show a patch of plaster that just peeled off. I am having this exact problem on a 3 1/2 year old plaster job.

 

[dumbcluck]

Would this be a considered a “bond” issue?
My contract includes 5,year warranty for bond only.

 

[onBalance]

It depends on whether the contract warranty is speaking about a "plaster bonding failure" or an "electrical bonding failure."

 

[dumbcluck]

Plaster specifically .

 

[onBalance]

Then you should be able to request that this problem comes under warranty.
Calcium nodules are generally indicative of bond failure, and then cracks develops, and then calcium nodules form on the cracks.

 

[dumbcluck]

Good stuff to know. Thanks. I wasn’t sure about the nodules, I was thinking more about where the grapefruit sized piece of plaster fell off in the deep end.

 

[Megsyperk]

Then you should be able to request that this problem comes under warranty.
Calcium nodules are generally indicative of bond failure, and then cracks develops, and then calcium nodules form on the cracks.

Hi Onbalance, question for you. Would a calcium nodule on day 5 post replaster be a sign that there’s way more to come? Or is it possible that it’s isolated and can be taken care of with your underwater fix suggestion? My pool builder is coming on Monday to see what’s going on, and I just want to know what’s reasonable for me to ask in this scenario.