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Permalink Reply by Anders Olsen on March 9, 2011 at 9:06pm

You need to make sure your pH is kept in check. It will tend to increase initially with a gunite pool. Your CH (Calcium Hardness) should also not be too high but if your pH gets above 8.0 it is virtually impossible to avoid calcium deposits.
I would encourage you to get a good test kit (drop based - not strips) and get to know the chemistry of your pool to avoid problems like this. You can calculate your CSI (Calcite Saturation Index) from the pool calculator at Poolcalculator.com

Good luck.

P.S. IMHO, it doesn't sound like a very impressive pool maintenance company you have if they have not been able to troubleshoot this one.....

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Permalink Reply by Pentair Product Technician-Ben on March 10, 2011 at 7:20am

Adding to what Anders stated, with a plaster pool the calcium hardness of the water plays a very important role.  If it gets off, the calcium will get pulled out of the plaster.  Once it hits the intellichlor it will get converted to a calcium deposit.

 

I'd like to know your chemical levels to get a better picture though.

 

Gallons in your pool (or at least the depths and I'll calculate)

Free chlorine

Ph

Alkalinity

Calcium hardness

Salt level

Water temperature

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Permalink Reply by Jeremy doig on March 27, 2011 at 10:14am

I get this occasionally. It usually means I need to add acid and clean out the chlorinator.
I find the chlorinator gets very gunked up with calcium deposits, so give it a good acid wash every 6 months.
In the first year, this problem was worse, but is not as severe in the last 2 years.

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Permalink Reply by William J Marshall` on April 5, 2011 at 9:36am

I've been told that when the Intellichlor goes through its automatic cleaning cycle it will flush calcium deposits into the pool. These have been picked up by the pool cleaner and I occasionally see them in the cleaner bag.  I see this only in the summer when the Intellichlor is working.

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Permalink Reply by Mervyn Trollip on April 5, 2011 at 1:11pm

We have encountered this problem many times in the nature reserves near the kruger national park in South Africa. The area is known to have a very hard water (high calcium hardness above 400ppm) short of trucking water in we have had to learn to cope with it. We use metal sequestriants (phosphoric acid) to reduce scaling, installing pH controlling units have been helpful in controlling pH that runs away. Lastly we set the Intellichlor units to change polarity in a shorter time frame to reduce the build up. We sacrifice a little of the life-span but cut down on maintenance.

Hope this helps a little.

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Permalink Reply by Pam Perry on January 22, 2012 at 7:03am

We have a new  gunite pool (4 mos old) and have developed calcium deposits.  Our pool guy consistently has tested the water with a drop based kit and the PH is in acceptable levels.  He mentioned that he seems to find this problem on pools that are heated more regularly.  Could heating a new gunite pool cause calcium deposits? 

Anders Olsen said:

You need to make sure your pH is kept in check. It will tend to increase initially with a gunite pool. Your CH (Calcium Hardness) should also not be too high but if your pH gets above 8.0 it is virtually impossible to avoid calcium deposits.
I would encourage you to get a good test kit (drop based - not strips) and get to know the chemistry of your pool to avoid problems like this. You can calculate your CSI (Calcite Saturation Index) from the pool calculator at Poolcalculator.com

Good luck.

P.S. IMHO, it doesn't sound like a very impressive pool maintenance company you have if they have not been able to troubleshoot this one.....

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Permalink Reply by Anders Olsen on January 22, 2012 at 3:58pm

In new pools, the pH does increase quite rapidly so if the pool guy just checks once a week, you could have the problem just before he shows up. I would recommend you check the pH yourself every 1-2 days. It is very simple and mostly important the first year.
Furthermore, when you heat the pool you have more CO2 outgassing which further increases the pH level. You just need to add a little muriatic acid to bring it back within the acceptable range where you will not have deposits.

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Permalink Reply by Pentair Product Technician-Ben on January 23, 2012 at 6:51am

Also, check your alkalinity and calcium harness levels as both can cause calcium issues.  As Anders stated, you should be checking much more often on a new gunite pool.  This style pool will have a large acid demand for at least the first few months.

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