White Haze (Not Calcium) on Stones

[Matchless1]

I hit a few of these spots with acid, but it doesn't faze them.



Any idea what these are, what could be causing them and how to get rid of them? Here my numbers taken today:

FC = 7
pH = 7.7
TA = 65
CH = 250
CYA = 42

 

[Patrick_B]

If they don't react with acid, Im not sure what to suggest other than mechanical removal, but I know that doesn't sound appealing. It wouldn't to me, and I'm sorry I dont have a better answer.

 

[Jimrahbe]

Match,

Sorry, I'm not sure of the answer either.. But, do have a question.

Was your picture taken at the flow-over of a waterfall of some type? If so, do you also this this issue at other places on your coping?

Thanks for posting.

Jim R.

 

[JoyfulNoise]

Do you know what type of stone that is?

I'm also interested in Jim's question - is it isolated to that area or do you see it in other spots?

Here's something I'd like you to try in a very small spots that's not too noticeable - get a small plastic cup and put some CLR liquid cleaner in it; do not dilute it. Find a small stiff toothbrush (maybe buy one) or if you happen to be at the hardware store, buy one (preferably nylon or Tampico, non metallic). Then dip the brush in the CLR and scrub a small area with lots of elbow grease and let a small puddle sit for about 5-10mins (preferably shaded so it doesn't evaporate). Mop up whatever liquid is there with a sponge and then rinse it off with some fresh water. Let it dry and see if the stain is lightened or removed.


Sent from my iPhone using Tapatalk

 

[Matchless1]

Match,

Sorry, I'm not sure of the answer either.. But, do have a question.

Was your picture taken at the flow-over of a waterfall of some type? If so, do you also this this issue at other places on your coping?

Thanks for posting.

Jim R.

Yes, the picture was of the flow-over of the waterfall. The rocks are "Creek Rock" and "Arkansas Builders". It's pretty confined to where pool water is in contact with the stones, but there are few other places on my rock wall (same rocks, but very little contact with pool water) where it occurs. It does not occur on the flagstone coping.

Do you know what type of stone that is?

I'm also interested in Jim's question - is it isolated to that area or do you see it in other spots?

Here's something I'd like you to try in a very small spots that's not too noticeable - get a small plastic cup and put some CLR liquid cleaner in it; do not dilute it. Find a small stiff toothbrush (maybe buy one) or if you happen to be at the hardware store, buy one (preferably nylon or Tampico, non metallic). Then dip the brush in the CLR and scrub a small area with lots of elbow grease and let a small puddle sit for about 5-10mins (preferably shaded so it doesn't evaporate). Mop up whatever liquid is there with a sponge and then rinse it off with some fresh water. Let it dry and see if the stain is lightened or removed.


Sent from my iPhone using Tapatalk

I can give it a try...need to get some CLR cleaner though. I have plenty of old tooth brushes.

 

[sham]

I have a similar problem which builder and stone guys say is efflorescence. They cleaned it with acid but as soon as it dried, the white came back. It is so odd, the white areas are not visible when the stone is wet. It is very visible when it is cold (30 degrees or so). It started appearing in winter when it got cold. Other times when its warmer it is not visible at all. They say sealing the stone will help prevent it but I'm not convinced. I'm going to have them seal a few spots to see if it helps.

We have it on the top and edges of coping and on the rock retaining wall. Water is not really hitting all the areas where it appears.

 

[Matchless1]

Well, the CLR didn't faze it either. I applied it just like you said, but no difference at all unfortunately.

 

[JoyfulNoise]

Based on what you're reporting, it's not a calcium carbonate. It's more likely a calcium silicate or some siliceous material, i.e., containing silicon dioxide. Silicates can be drawn from stone as much as carbonates can when efflorescence is the cause. It's just typically carbonates that we mostly see.

Try this next - get some fine grit (800 or so) wet/dry sand paper or sanding sponge and go over a small area. See if it is easily removed. Then wait to see if it returns. If it does return, you might need to consider lightly grinding the stone and then sealing it.


Sent from my iPhone using Tapatalk

 

[Matchless1]

Based on what you're reporting, it's not a calcium carbonate. It's more likely a calcium silicate or some siliceous material, i.e., containing silicon dioxide. Silicates can be drawn from stone as much as carbonates can when efflorescence is the cause. It's just typically carbonates that we mostly see.

Try this next - get some fine grit (800 or so) wet/dry sand paper or sanding sponge and go over a small area. See if it is easily removed. Then wait to see if it returns. If it does return, you might need to consider lightly grinding the stone and then sealing it.


Sent from my iPhone using Tapatalk

The finest I had was some 200 grit, so I tried that. It definitely seemed to help remove it. Although it's been kind of drizzly and overcast all day, so the stones haven't really had a chance to dry out for me to see what still remains. Rain is forecast through Tuesday, so maybe by Wednesday I'll get a better look at it and be able to remove more based on what I can see. Thanks for the tip.

I actually sealed those stones (as well as all of the stones on the waterfall, coping, steps and rock wall) before starting up the pool last July. Guess it's time for a re-seal at least of those particular stones since they see so many wet/dry transitions being on the waterfall edge. What I'm wondering though is if I also need to extract all the rocks at the bottom of the falls, as well as the water that sits in that little trough, and seal the back of those rocks/mortar. I'm pretty sure they Drylok'd all those after building, but it seems apparent that water is likely coming from the back side and escaping through the top of the rocks causing this. I will point out that I have the falls set to kick on every 4 hours for 2 minutes just to keep the water from getting stagnant. I do the same for my slide, but just once a day for a minute to keep the water in that pipe from sitting as well.

Here's a photo of the trough that I'm talking about.

 

[Matchless1]

I guess it's time to revive this thread, since the white haze seems to be getting worse (mainly on the WF stones, but others on other parts of my stone wall as well). Today I tried using sand paper and vinegar, which I've seen lots of posts on here and YouTube recommending. It actually seemed to make it look a little worse if I didn't know any better.

Again the acid doesn't faze it, neither does the CLR cleaner. Here are some recent pics of the worsening condition. Any new suggestions on things to try or test for would be extremely appreciated! The pool's not even a year old and I feel like I have a long battle ahead of me if I can't figure out a solution soon. Feeling helpless!

 

[mknauss]

Efflorescence? It is the minerals in the stone naturally being released now that they are open to the air compared to when they were in their natural state.

Typically takes a very long time for it to dissipate.

Maybe some one else has a suggestion.

Take care.

 

[JoyfulNoise]

Grinder.

Efflorescence can involve silicates as well which won't respond to acid. You'll need to use a fine grit paper to take it off.

 

[Ecoke]

Try this....Home Depot...Lowes...or local hardware. Follow instructions and proper PPE. (Personal protective equipment)



- - - Updated - - -

Try this....Home Depot...Lowes...or local hardware. You will find it in the bagged concrete area. Follow instructions and proper PPE. (Personal protective equipment)

 

[mknauss]

The QuikRete product is a dilute acid. So if your efflorescence is calcium based, it will work. If silicate, it will not.

Take care.

 

[Matchless1]

The QuikRete product is a dilute acid. So if your efflorescence is calcium based, it will work. If silicate, it will not.

Take care.

I had already ordered this stuff before the QuikRete product was posted: https://www.amazon.com/gp/product/B00UW1C1QI/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

I used this along with 400 grit and 1200 grit wet/dry sand paper. Nothing, still! This is insane. I really hate to take a grinder to these stones and ruin the natural look, not to mention having to do that every few months will be a huge PITA. It's so bad now that it's on just about every stone face under the waterfall. I'm beginning to suspect it must be silicate based, but what else can I try if that's the case?

 

[cfherrman]

Wire wheel with a grinder, just a guess

 

[JanHan]

Maybe the grout has a latex or poly additive leaching out? Could you try dabbing a little bit of lacquer thinner in a less conspicuous spot to test?