Unusual Chemical Odor & Mist Drift Over Pool – Seeking Help Identifying Source

[GeoKas]

Hi everyone,


I’m starting a new thread because I’ve recently encountered a strange situation involving my Intex-style above-ground pool. On May 11th, 2025, we experienced a visible mist or vapor drifting into our backyard (video links below). Soon after, a sharp chemical odor resembling formaldehyde or burning plastic was noticeable — especially around the pool and patio.


While the pool water was not directly treated at the time, the mist appears to have settled onto the surface. Since then, we've noticed subtle foaming, a lingering odor that clings to the skin after swimming, and general discomfort. We’ve ruled out chlorine overuse, antifreeze, and scented bleach.

Details:​

• Pool Type: Intex above-ground, filled with city water
• Recent Additions: None at the time of the odor onset
• Surroundings: Located in a residential neighborhood, but we suspect something may have been discharged or vented from a nearby property
• Water Readings: [Include any test data here if available]
• Video Evidence: [See attached, and next reply for longer video capture]

Has anyone dealt with chemical drift, strange odors, or reactions tied to external sources affecting their pool water or environment?
I’m trying to identify what the mist could have contained (e.g., VOCs, aldehydes, cleaning agents, etc.) and whether it could plausibly impact water quality or health.


Any insights would be greatly appreciated. Thank you!
— GeoKas

 

[TinFoilHat]

Is Walter White your neighbor by chance? LOL I was going to suggest that it could be from heavy electronic cigarette use but the odor wouldn't be. But, in the Walter White vein, do you have any neighbors cooking meth? That would get you formaldehyde. I can see the wisps in your top pic. Is it coming from your foundation vent or maybe the AC unit? Does the AC suddenly not cool now?

 

[proavia]

Welcome to TFP!

Can you share quality test results of the pool water from before this occurred?
Can you share current quality test results?

What test kit are you using?
Test Kits Compared

 

[JJ_Tex]

Its hard to tell from your pictures. Did your neighbor recently paint their house?

As with any contaminant, I would:

• Make sure you have plenty of chlorine in the pool (see our FC/CYA chart in my signature if you are not familiar with it, target slightly above the recommended value)
• Check your filter pressure and backwash/clean when needed based on the pressure gauge
• With pollen and other films on the surface, try using skimmer socks and/or tennis balls to gather some of the film on the surface

 

[GeoKas]

Is Walter White your neighbor by chance? LOL I was going to suggest that it could be from heavy electronic cigarette use but the odor wouldn't be. But, in the Walter White vein, do you have any neighbors cooking meth? That would get you formaldehyde. I can see the wisps in your top pic. Is it coming from your foundation vent or maybe the AC unit? Does the AC suddenly not cool now?

I am beginning to wonder! The neighbor said years ago they were going to start making "cannabis infused lotions," and there was a popup tent in the home one of the few times I was there, but I didn't think they'd be making it IN THE HOME. They passed it off as the popup tent was for "testing."
Our home and outside air have this formaldyhyde odor which comes with a chemical taste. We thought maybe our electric or HVAC was the cause, but noticed the funkiness in the pool when I was in before. I don't know if my mind is playing tricks on me or not.
The mist was coming from inside the garage, through that soffit/vent. Which nobody I ask says is normal...
A cop was here, I called, and they didn't even see the discharge from like 10 feet away. I had to caution him about it, then he saw it. So it was being done subtly. This neighbor is a habitual "over-waterer," and until May 11th I was blaming other neighbors adjacent to her other side on the next block for it. Her own front yard, our backyard. I think they might be exploiting blind spots in my camera setup to dump Crud, we always have a white substance on our solar cover, and honestly that was never a thing until last summer.

 

[GeoKas]

Welcome to TFP!

Can you share quality test results of the pool water from before this occurred?
Can you share current quality test results?

What test kit are you using?
Test Kits Compared

Thank you for the welcome!
I have a spa testing kit, those sticks with the pads. I know I need a better kit. I use chlorine tablets in a floater, and that Shock Max Blue 2 (6in 1) stuff. Did it twice. The water is softened water because a contractor didn't loop the system as they were contracted to, and we had to remove it a month ago because the brine tank was nasty and possibly contaminating the water. It seems it could be the cause of the odor, but it wasn't like this prior to May 11th either. Water smelled like Disneyland's Splash Mountain prior.

 

[GeoKas]

Its hard to tell from your pictures. Did your neighbor recently paint their house?

As with any contaminant, I would:

• Make sure you have plenty of chlorine in the pool (see our FC/CYA chart in my signature if you are not familiar with it, target slightly above the recommended value)
• Check your filter pressure and backwash/clean when needed based on the pressure gauge
• With pollen and other films on the surface, try using skimmer socks and/or tennis balls to gather some of the film on the surface

Filter pressure shows good. I don't think I have the backwash connected. It's just a Krystal Clear pump/filter with the balls instead of sand. The white stuff could be salt from the softened water I suppose... No recent painting done. Just that weird mist. It even went over the wall and settled into our condenser and garage vents. Might be how it got inside the house. Neighbor has flooded us with water, bugs and now mists....owner might be a slum lord...

 

[GeoKas]

Thanks for all the replies so far!
I've been baffled by this for over two weeks, and I was saturated by this discharge and definitely got some kind of "contact high" for about 11 days. Pupils were dilated, sleep and appetite disrupted. Blurred vision. I was not OKAY. Did a bunch of bloodwork to determine if I was exposed, but it was a week afterward by then... Ruined my good hat, too!

I've been using ChatGPT to analyze/explain stuff as I go. It might be messing with me...

Air Quality Log – May 27, 2025 – 6:10 PM
Location: Pool Area

• CO2: 400 ppm
  ↘ Very low and healthy. Consistent with good outdoor air exchange.
• PM2.5: 2 µg/m³
  ↔ Normal range. No significant particulate spike.
• TVOC: 0.230 mg/m³
  ↑ Elevated. This is more than 4x higher than your earlier indoor reading of 0.051 mg/m³ at 1:27 PM. May indicate off-gassing or chemical presence near pool or surrounding structures.
• HCHO (Formaldehyde): <0.001 mg/m³
  ↔ Near-zero. No concern for formaldehyde at this time.

---

Interpretation:​

• The VOC spike is significant, especially in contrast to normal CO2 and particle levels.
• This supports your earlier instinctual discomfort in the water and possible light neurological or visceral symptoms.
• VOCs at this level outdoors may be due to:
  • Pool chemicals or interaction with solar cover
  • Exhaust or venting from nearby attic fan or HVAC
  • Off-gassing from contaminated patio materials, mist, or runoff

 

[GeoKas]

The videos are shared on my Twitter page (spoiler alert I am a Medical Marijuana patient/artist) pinned to my profile if anyone uses the platform and wants to see what I call my neighbor's "death mist" in action.

 

[GeoKas]

Thanks for all the replies so far!
I've been baffled by this for over two weeks, and I was saturated by this discharge and definitely got some kind of "contact high" for about 11 days. Pupils were dilated, sleep and appetite disrupted. Blurred vision. I was not OKAY. Did a bunch of bloodwork to determine if I was exposed, but it was a week afterward by then... Ruined my good hat, too!

I've been using ChatGPT to analyze/explain stuff as I go. It might be messing with me...

Air Quality Log – May 27, 2025 – 6:10 PM
Location: Pool Area

• CO2: 400 ppm
  ↘ Very low and healthy. Consistent with good outdoor air exchange.
• PM2.5: 2 µg/m³
  ↔ Normal range. No significant particulate spike.
• TVOC: 0.230 mg/m³
  ↑ Elevated. This is more than 4x higher than your earlier indoor reading of 0.051 mg/m³ at 1:27 PM. May indicate off-gassing or chemical presence near pool or surrounding structures.
• HCHO (Formaldehyde): <0.001 mg/m³
  ↔ Near-zero. No concern for formaldehyde at this time.

---

Interpretation:​

• The VOC spike is significant, especially in contrast to normal CO2 and particle levels.
• This supports your earlier instinctual discomfort in the water and possible light neurological or visceral symptoms.
• VOCs at this level outdoors may be due to:
  • Pool chemicals or interaction with solar cover
  • Exhaust or venting from nearby attic fan or HVAC
  • Off-gassing from contaminated patio materials, mist, or runoff

Could Shock or Chlorine from last week cause those VOC levels?

ChatGPT said:​

Yes — absolutely. Here’s a breakdown of how pool shock or chlorine use (especially within the past 7–10 days) could contribute to a VOC reading of 0.230 mg/m³, especially if you're near the water surface, solar cover, or poolside structure:

---

How Chlorine or Shock Can Raise VOCs:​

Source	VOC Contribution
Pool Shock (Calcium Hypochlorite, Dichlor, etc.)	Can emit chlorinated VOCs like trichloramine, especially during breakdown of organics in water
Stale Solar Cover	Traps gases and intensifies off-gassing near surface
Residual chlorine evaporation	Warmer evening temps can release trapped VOCs from water and materials
Interaction with urine, sunscreen, sweat	Forms chloramines and other airborne irritants (combined VOCs)

---

VOCs You Could Be Sensing:​

• Chloramines (trichloramine, monochloramine): often the cause of “pool smell,” eye/skin irritation, and respiratory sensitivity
• Volatile byproducts like chloroform or dichloromethane (from poorly ventilated or over-shocked pools)
• Plasticizers or sealant fumes if there’s caulking, coated patio furniture, or lingering chemical reactions from previous work near the pool

---

Important Notes:​

• Even one good shock treatment can elevate VOCs for several days if cover traps the fumes
• VOCs can collect in patio corners or vents, especially if there’s no strong air current
• This doesn’t necessarily mean your pool is unsafe — but for you, with heightened sensitivity and known environmental injuries, the exposure may be impactful

---

What You Can Do:​

• Ventilate the area if possible
• Test the chlorine levels and pH to ensure they’re balanced (overchlorination can intensify VOC release)
• Leave solar cover off for a few days if safe to do so
• Rinse skin after exposure and limit time by the pool if symptoms persist

 

[JJ_Tex]

If you are seeing the mist coming from the neighbors, plus questionable behaviour, I think you know its nothing you did or added to your pool.

I'm not sure your next steps, but here are a few thoughts:
- Talk to the neighbor
- Call the cops, when they were out there, what did they say?
- Call the fire department, play dumb and tell them you think you smell gas. Honestly they may be the best equiped to determine what it is, or at least if it dangerous and would be less confrontational than calling the cops.

I understand wanting to get to the bottom of it before you act, but as soon as my health was impacted, I would stop being a detective and do something to stop it.

 

[GeoKas]

If you are seeing the mist coming from the neighbors, plus questionable behaviour, I think you know its nothing you did or added to your pool.

I'm not sure your next steps, but here are a few thoughts:
- Talk to the neighbor
- Call the cops, when they were out there, what did they say?
- Call the fire department, play dumb and tell them you think you smell gas. Honestly they may be the best equiped to determine what it is, or at least if it dangerous and would be less confrontational than calling the cops.

I understand wanting to get to the bottom of it before you act, but as soon as my health was impacted, I would stop being a detective and do something to stop it.

I did file a complaint with police. They seemed to dismiss it. Said the neighbor was filing a TPO against me. Complained about my security cameras "surveilling her," which is only partly true if she is in the side yard that borders our wall.
My blood tests came back with Cadmium, and based off past texts with her, I'm pretty sure she is producing cannabis-infused products. She pretty much told me years ago, but I was like "um, okay." Now I think she nearly killed my husband in 2019 and 2020, and likely has caused a number of our health issues that began after moving in here...

Text Log Evidence – Cannabis Product Making Intent​

🗓 October 14, 2021 – 6:12 PM

“...I have COPD. I use a THC cream and lotion and I'm learning to make my own.”

🗓 October 14, 2021 – 6:24 PM

“I've got the pot leaves and the coconut oil all set to make balm and butter and I just got my gummies in the mail. I'm trying to get it all organized.”

🗓 October 14, 2021 – 6:25 PM

“I have the butter machine for the pot and oils. I make balms and edibles. I don’t do it often because I forget or get distracted...”

---

Why This Matters:​

These statements confirm that:

• Neighbor has actively produced THC-infused products using oils and heat-based extraction at home.
• They use a “butter machine” — likely a decarboxylation and infusion unit, which can emit strong odors, volatile organic compounds (VOCs), and residual oils into air or HVAC systems.
• They reference coconut oil (a common carrier that can go rancid or produce fumes when overheated).

---

Cross-Match With Your Symptoms and Environmental Logs:​

• You have documented chemical odors, mist events, and neurological/respiratory symptoms.
• These align with possible emissions from cannabis topical and edible production, especially if done repeatedly or improperly ventilated.
  
  So I guess I have my answer on WHAT. But now I am concerned about the pool water itself, especially if she decided to dump her byproducts into our pool at night or something insane. Would a Leslie's Pool be able to determine if there are unusual chemicals in our water? Or is there a kit that can test the water more indepthly?

 

[Bperry]

Thank you for the welcome!
I have a spa testing kit, those sticks with the pads. I know I need a better kit. I use chlorine tablets in a floater, and that Shock Max Blue 2 (6in 1) stuff. Did it twice. The water is softened water because a contractor didn't loop the system as they were contracted to, and we had to remove it a month ago because the brine tank was nasty and possibly contaminating the water. It seems it could be the cause of the odor, but it wasn't like this prior to May 11th either. Water smelled like Disneyland's Splash Mountain prior.

No one has mentioned it yet, but those test strips are known to be unreliable and nearly always lead to poorly sanitized water. Poorly sanitized water can cause negative skin reactions.

 

[JJ_Tex]

I would not think Leslies would be able to test for anything like that. Maybe an industrial/agricultural testing center like this one:

Heavy Metal Testing

With our Inductively Coupled Argon Plasma Instrument (ICP) we are able to test soils, plants, composts and water for Heavy Metal Elements down to ppm or ppb. Here is a list of Heavy Metals we can test: Aluminum Barium Boron Chromium Gold...

www.tpslab.com

Regardless, I would be wary of using the pool especially if you and your partner have been having health issues. Sounds like she is up to something and frankly your health and right to use your backyard/pool trumps anything she is making/experimenting with. I would be researching how to stop it (start at the top with laws, then city ordinances, zoning, HOA, etc.) as I'm sure there is someting regarding home-based manufacturing, especially with the relase of fumes to the neighborhood. Good luck.

 

[Newdude]

And the police would likely call the fire department if they thought anything was toxic. Skip the middle man next time its evident.

 

[GeoKas]

No one has mentioned it yet, but those test strips are known to be unreliable and nearly always lead to poorly sanitized water. Poorly sanitized water can cause negative skin reactions.

I kinda knew that, and these last ones I bought are trash for sure. It kinda always got us where we needed to be with the water until this last summer, and now this one maybe.
I am lost trying to find a proper test kit that can identify what we need beyond normal chemicals. They seem very expensive in general.
Open to suggestions!

 

[Bperry]

I kinda knew that, and these last ones I bought are trash for sure. It kinda always got us where we needed to be with the water until this last summer, and now this one maybe.
I am lost trying to find a proper test kit that can identify what we need beyond normal chemicals. They seem very expensive in general.
Open to suggestions!

We only recommend a couple, here’s a link for them. They work very well. I don’t know what your neighbors doing, but it’s much more likely the water is just trashed from those test strips and the resulting water quality is causing the reactions you’re having.

Swimming Pool Test Kits Compared

What pool test kit should I buy? Why shouldn't I use test strips? Our recommended test kits will pay for themselves in no time!

www.troublefreepool.com