Rust specks on pool walls and baja but not in attached raised spa?

[tomas21]

What are these?

I recently noticed what looks like tiny specks of rust on our pool walls and in some spots our baja shelf and steps..... These tiny specks don't seem to exist in our raised attached spa walls, seats or steps

Hydrazzo Mediterranean blue was installed ~4 months ago and just started to notice this... trying to come up with theory on cause and if it is something to try to fix or just live with..

Attached are some pics of the tiny reddish/orange specks... seems to be random on various walls.. can't really tell if on the pool floor.

Not sure if..
- Was something in the mix and now starting to show up
- Water source but why on the walls throughout and not the attached raised spa
... ...

Curious thoughts and potential solutions.

 

[Texas Splash]

Hard to tell. Specs like that don't really seem like iron we would see from water conditions from a well or something. To be sure it's iron material, have you tried rubbing a Vitamin C tablet on one of those marks? Once confirmed, perhaps place a small magnet on those stains to see if it sticks which could be indicative of metal (i.e. rebar) being too close to the surface.

 

[tomas21]

I have not tried anything but assessing pictures of shotcrete in those specific areas and all are clean with no rebar, wire tie, etc.

 

[Texas Splash]

I have not tried anything but assessing pictures of shotcrete in those specific areas and all are clean with no rebar, wire tie, etc.

Well, with no metal in that area, I would confirm with the Vitamin C test just to be sure. If iron is confirmed, it may have been introduced by your local water supply. Sometimes iron residue can hit the pool from nearby sources and settle on the floor leaving such marks. Why you have it on the walls is odd since you ruled-out anything behind the walls. Or, as I believe you mentioned in your first post, perhaps some impurities were mixed in with the shot and it's just now showing itself. Once remove with Vitamin C, it may not come back.

 

[tomas21]

Well, with no metal in that area, I would confirm with the Vitamin C test just to be sure. If iron is confirmed, it may have been introduced by your local water supply. Sometimes iron residue can hit the pool from nearby sources and settle on the floor leaving such marks. Why you have it on the walls is odd since you ruled-out anything behind the walls. Or, as I believe you mentioned in your first post, perhaps some impurities were mixed in with the shot and it's just now showing itself. Once remove with Vitamin C, it may not come back.

I hope that is the case with just some impurities in the Hydrazzo mix that are just now showing themselves at the surface that can be quickly remediated with Vitamin C spot treatment since the they are basically tiny orangish/red dots with a slight smear... Will report back on Vitamin C test

 

[mknauss]

Was abalone shells added to the plaster?

 

[tomas21]

Was abalone shells added to the plaster?

The plaster was bagged Hydrazzo Mediterranean Blue with nothing added.

 

[tomas21]

Update: I applied some elbow grease with some small vitamin c to the tiny specs on the walls and baja shelf area. With some elbow grease in a circular motion and a tiny circular vitamin C I was able to remove "most" of the visible specs from my perspective.. maybe a little residual left in the tiny cavity of the Hydrazzo?

It is interesting that the Hydrazzo is polished but the specs seem to protrude a little above the surface and are maybe in a tiny little cavity of the polished finish.....

Wondering what might be the cause since this hasn't appeared until now (~4 months after Hydrazzo install and polish) and the pool parameters have been balanced

Possibilities... ?
- Something in the original hydrazzo mix that is at the surface?
- I do recall during Hydrazzo install the plaster crew dropped a tool of some sort in the mix hopper not sure if that did anything
- Our water source from City may have some type of metal that adheres itself inside the tiny tiny cavities in the walls and some bottom areas I can see like the baja.. haven't been able to dive down and look at deep end
- What is strange is I don't see anything in the attached raised spa

Curious what other think could be cuasing this and again the specs are tiny like a mechanical pencil tip-ish

 

[Texas Splash]

I would think if your water was over-saturated with iron, there would be evidence in other areas. Still you could have a water sample tested at a local store to see what they show for iron and copper levels. The Vitamin C tabs should not require aggressive scrubbing to remove iron though. The acid in the tablets is usually sufficient enough to cause a removal reaction, so now I can't help but wonder if it's something else. Have you used any copper-based products lately? Now might also be a good time as a formality to post a full set of your own TF-100 water test results. Just to make sure nothing odd stands out there. Lastly, you can Google your local water municipality's annual water report to see what they show for metals. If all of these don't prove anything out of the ordinary, it may just some particulates in the mix that was applied.

 

[tomas21]

I have not used any copper-based products.

I reviewed our Hydrazzo install video and the spa was the last area to be plastered.. in case the theory was majority of bags had some particulates in them but the last bags for spa were fine... long shot.

Here is the Latest annual water report which looks pretty clean..

I'll do a full test of FC, pH, TA, CH, CYA tomorrow and report back

 

[tomas21]

@Texas Splash parameters reading
FC - 1.0
pH - 7.6
TA - 50
CH - 300
CYA - 55
TEMP - 53
CSI - -0.63

 

[Texas Splash]

There is nothing in those results that would indicate a chemistry correlation. The FC is a bit low, but your water is chilly to keep organics at bay. That should have no bearing on those specific spots you are seeing. Thanks for posting for our validation.

 

[Megsyperk]

I have the same exact thing going on — and our current theory is that roof shingle granules blew into the pool while they were replastering. It was rather windy the day the plaster went on and it’s the only explanation we can think of that would cause the vertical spots. The spots are inconsistent so I’m doubtful it was in the mix itself, some areas of the pool have no spots.