Spa plaster flaking

[bk406]

The sanitizer cannot get "through" the hardness well enough to assimilate in to the water efficiently. .

What does this mean exactly? Whats the chemical basis for this assertion? Yes, high calcium will cause scaling and rising pH can make the problem worse. Yes, 1000 ppm calcium levels are not good. But...I'd like to know a little more about how the chlorine can not "get through" the hardness.
Calling chemgeek!

 

[bk406]

A pool's surfaces still needs care, in addition to the water balancing. Regular vacuuming and brushing, emptying baskets, adequate filter cycles all contribute to a clean and healthy pool.

Scott

Yea, sure i get all that
My point was/is that out of control algea was origiannly brought on by inadequate chlorine levels to begin with. Brushing, cleaning, and keeping the water balance to maintain a pool is a given. IMO, high calcium levels or high overall TDS does not cause chlorine to work less efficiently. High CYA means you need more of it (chlorine that is) , but i cant figure out how high TDS in and of itself causes chlorine to not be able to "get through". I'm just looking for a real chemical reason why this is so.

 

[PoolGuyNJ]

I had never heard old water having a meaning in that context. Sorry for my earlier statements possibly coming across somewhat crass.

I don't know of any direct effect on chlorine due to high calcium. That being said, high calcium levels need a lower pH to stay in solution and avoid scale formation. If someone drops the pH far enough below 7.0 for more than a few days, chlorine will loose it's effectiveness as a sanitizer and the potential for an algae bloom exists. I think this happened to you because the calcium flakes are evidence of a battle against scale. Either that or you over corrected accidentally and it wound up being a good thing.

People who are relatively inexperienced often have difficulty when there are multiple issues happening at once. I know I did when I was a newbie with computers, networking, cars, pools, and a whole host of other things. I will be again with something, probably sooner rather than later.

Scott

 

[bk406]

. Sorry for my earlier statements possibly coming across somewhat crass.

No problem. Didnt take it that way

I think this happened to you because the calcium flakes are evidence of a battle against scale. Either that or you over corrected accidentally and it wound up being a good thing.

i'm not the OP. I was just curious as to what Simi meant by old water and the chlorine not being able to get in. Sorry for the confusion.

 

[JasonLion]

Old water, in this area, gets extremely high levels of calcium, and it is impossible to keep chlorine levels and water balance in a hard water pool. The sanitizer cannot get "through" the hardness well enough to assimilate in to the water efficiently. This is why pool water is suggested to remain in a 200-400 ppm range for calcium hardness.

Water that has 1,000+ ppm water is just too "old" and hard and needs to be drained (or treated). Way too hard to control algae and maintain proper levels of sanitizer in that hard of water.

In most situations it is best to keep CH levels under 400. In some cases that is impractical and CH must be allowed to rise higher. In extremely arid conditions with high CH fill water, CH must sometimes be allowed to rise as high as about 1,200. Beyond that level, even with careful management of PH and TA levels, it becomes impractical to reliably prevent calcium scaling and it is best to replace the water, or hire a treatment service, to lower CH levels.

But nothing about high calcium levels has any meaningful impact on chlorine, nor does it encourage algae. Target FC levels remain the same, based on your CYA level, and algae is kept away just as it would be at lower CH levels.

---

Calcium scaling is most likely to occur in the heater and SWG first. Higher temperatures promote calcium scaling, as do the chemical processes inside a SWG cell. Sometimes the cycles of thermal expansion and contraction that occur when the heater heats up and cools down can cause calcium scale inside the heater to break lose. A similar situation exists in the SWG, except that the SWG intentionally reverse operation to encourage the scale to flake off. Scale from a SWG tends to show up as flakes, while scale from the heater tends to be less uniformly shaped.

In any case, a full set of water tests should be done and the calcium saturation index calculated, to see if you need to adjust your water balance to prevent this scaling.

 

[PaulR]

"Old water" has some meaning in a standalone spa, where after some number of months the chlorine demand will tend to rise even with everything else nominally balanced, and you just replace the water. But in a pool, or spa connected to a pool, that doesn't really seem to be a factor.
--paulr

 

[Guest]

Just curious.. has anyone used bottled filtered water as their pool fill and maintained their chemical levels?

 

[PoolGuyNJ]

I just can't see 2000 five gallon bottles being emptied into a freshly plastered 10K pool.

Oops, one slipped. Thwunk. Hope nobody notices the dent.

Which one of you guys took the empty bottles for change holders? The delivery guy says there are only 1998 empties.

Exclusive to the big screen stars, lemon flavored Perier pool water.

Scott

 

[Guest]

I just can't see 2000 five gallon bottles being emptied into a freshly plastered 10K pool.

Oops, one slipped. Thwunk. Hope nobody notices the dent.

Which one of you guys took the empty bottles for change holders? The delivery guy says there are only 1998 empties.

Exclusive to the big screen stars, lemon flavored Perier pool water.

Scott

Ah, Scott, you fell for it While you can't see it happening, it CAN happen, and it does (just not a bottle at a time!). The point being that if you don't know how a "bottled water" pool behaves you can't really say how well the water behaves with chemicals!

Stay tuned...... Bottled water pools (without the redemption value and return issues!) coming to a pool near you

 

[josta]

Hello again, I'm back after a few weeks of some more close observation of the pool and spa. The flakes are indeed in the spa only, and appear to be the plaster continuing to flake off, but now it's very small and thin pieces which is most noticeable at nighttime with the spa light on, like the liquid-filled "snow globes" that you shake for the "snow" inside of it. Because they're so small and thin I can't otherwise see any damage to the spa but what do I know? The plaster surface is pretty rough, though.

After the disastrous "acid wash" last fall, I've been brushing and vacuuming the spa only to have the flakes reappear after a few days.

I guess my question is, is it going to keep on doing this forever, or is my only option to replaster the pool? I had one guy come out, look at it and give me a price on the replastering but he did not give me any other options. Before I spend $2,000 doing so I just want to be sure that I have no other options.

 

[JasonLion]

I think that is is quite possible that the calcium flakes are coming from your plumbing, not the plaster. To be sure, you can put a stocking over the return, so any flakes coming from the return will be caught in the stocking. That way we can be sure if the flakes are coming from the plaster or from the plumbing.