Can water chemistry affect pool plaster ?

[JcSparky]

I would suggest that you turn off the autofill for a day to see if the pool is leaking.

If all you have used for the last 3 years is trichlor tabs, there's no way that the chemistry you posted earlier could be accurate unless you are replacing the entire volume of the pool on a regular basis.

We have gotten some good rain over the last week. Would this affect my numbers in anyway?

 

[red-beard]

Yes. It will dilute the pool.

 

[JcSparky]

I've turned off my auto fill and inline chlorinator a few minutes ago.

 

[JamesW]

Ok. The numbers really are not possible unless you have a huge leak or someone is adding something without your knowledge.

Watch the water level to make sure that the pump does not run dry.

 

[JamesW]

I've turn off my auto fill and inline chlorinator a few minutes ago.

You really don't want to turn the feeder to off because the tabs are soaking in water and they will continue to dissolve and create a very toxic, corrosive chemical stew.

 

[JcSparky]

You really don't want to turn the feeder to off because the tabs are soaking in water and they will continue to dissolve and create a very toxic, corrosive chemical stew.

Ok, I've turned the chlorinator on to a trickle but there's not much in there at moment.

 

[JamesW]

What month of the year was the pool plastered?

Are your water bills unusually high?

 

[JcSparky]

What month of the year was the pool plastered?

Are your water bills unusually high?

Installed June/July 2018 and my water bill is not unusually high. Probably plastered in July.

I've turned off the auto fill and will report the 24 hour difference tomorrow.

 

[JamesW]

Did you ever do the CYA dilution test?

What test kit do you have?

You should get the TF-100 with a salt test kit included.

 

[JcSparky]

I have the TF-100.

I did perform the CYA dilution test by mixing a cup of pool water and a cup of tap water. The result was 100. Assuming the CYA is high because of the tabs I've been using.

 

[red-beard]

I would dilute again, 3 cups tap to one pool. You need to get a CYA reading well under 100. I had a pool that was probably close to 1000, almost 10 years of tablets.

 

[JcSparky]

I would dilute again, 3 cups tap to one pool. You need to get a CYA reading well under 100. I had a pool that was probably close to 1000, almost 10 years of tablets.

Ok, 3-1 dilution gets me about a 65 CYA reading.

 

[red-beard]

So, a 260 CYA. You definitely need to do a drain to get to a reasonable CYA. You could do a 3/4 drain, and end up with 65 CYA.

 

[JamesW]

The CYA makes sense for the amount of tabs used, but the pH and TA just are not realistic.

At this point, we have a snapshot of the chemistry and we do not have the whole history.

There's really no telling what the chemistry has been up to this point.

The plaster is difficult to diagnose. There might be some "spot etching" and maybe some mottling.

Does the plaster feel rough?

Is the plaster soft and easy to scratch?

Is the plaster a different color than it was originally?

What specifically caused you to be concerned about the plaster now vs. before?

Are you 100% sure that you are doing the tests correctly?

Are you 100% sure that nothing has been added other than tabs?

Are you sure that the tabs have always been trichlor?

 

[JcSparky]

The CYA makes sense for the amount of tabs used, but the pH and TA just are not realistic.

At this point, we have a snapshot of the chemistry and we do not have the whole history.

There's really no telling what the chemistry has been up to this point.

The plaster is difficult to diagnose. There might be some "spot etching" and maybe some mottling.

Does the plaster feel rough? Yes, in the problem areas.

Is the plaster soft and easy to scratch? No.

Is the plaster a different color than it was originally? The plaster that doesn't appear damaged, no. The problem areas are definitely lighter.

What specifically caused you to be concerned about the plaster now vs. before? I noticed some small signs of issues sometime last year, but it is more pronounced this spring.

Are you 100% sure that you are doing the tests correctly? Yes, although I will re-do the tests today and will report if my numbers are drastically different.

Are you 100% sure that nothing has been added other than tabs? Yes.

Are you sure that the tabs have always been trichlor? My pool builder initially left me a small bucket, but I couldn't tell you what they were. I have been using the Suncoast trichlor for a couple of years now. I have ceased using them as of Saturday.

 

[JcSparky]

To get my CYA down, I plan on a partial drain this next weekend and refill. I will test before and after.

 

[JamesW]

The best thing you can do now is manage the chemistry correctly.

There's probably not much that can be done for the plaster.

Maybe drain and sand everything smooth.

Don't drain unless you can verify that it is safe to do so.

 

[JcSparky]

The best thing you can do now is manage the chemistry correctly.

There's probably not much that can be done for the plaster.

Maybe drain and sand everything smooth.

Don't drain unless you can verify that it is safe to do so.

What do you mean by "Don't drain unless you can verify that it is safe to do so." ?

 

[JamesW]

Pools can float and pop out of the ground if you drain while the ground water is high.

 

[ajw22]

What do you mean by "Don't drain unless you can verify that it is safe to do so." ?

The weight of the water helps hold the pool in the ground. Drained pools have popped out of the ground due to pressure of the ground water.

We have a water exchange process that can exchange pool water for fresh water without draining.

Read...

Draining - Further Reading

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