Brown spots on pool floor

[evan567]

Hello,

I recently purchased a home with a pool. Previously I had zero experience working with pools. We tried opening the pool ourselves and ended up with algae. Water was green and cloudy with noticeable algae floating on surface.

Couple weeks later, water is now crystal clear but we have brown spots scattered throughout the floor of the pool. When brushing it off it returns (not sure about if it returns to exact spot or not). And when vacuuming it to waste there seems to be an improvement but also seems to return in some places. Or I could just be missing spots. Sometimes they are so small that it is easy to miss at first glance.

After looking at stuff online it kind of sounds like yellow algae due to:
-Brushing causes it to poof up in a cloud
-It returns

But then these aren't happening:
-Doesn't appear to be on walls
-It is all over the pool not just in the more shady areas
-Water chemistry seems to be mostly fine and it is clear. We had high alkalinity that we got down and now pH is a smidge low.
-We are in the midwest and sounds like it is less common outside of the south.

I've tried touching it and seeing what it feels but it was just too hard to tell with 100% certainty because I have to go underwater (since it isn't on walls) and it immediately blows away when touched. There was one spot that maybe felt slimy but I think it felt gritty in other places.

I've tried asking a couple different pool stores about it and neither seemed concerned about it. Just mentioned vacuuming it out. If it is dirt/something that can be vacuumed out does it normally more than one go around?

We don't have a test kit yet but have been utilizing the pool store down the road. I understand that isn't ideal but here's the latest results from them:
FC: 3.86
TC: 3.97
CC: .1
pH: 7.1
Hardness: 197
Alkalinity: 146
CYA: 35
Copper: .3
Iron: .1
Phosphate: 1298

I'll attach some pictures. It is hard to pickup in photos but I'll post one and then another of same spot zoomed in. Would appreciate any suggestions on what it could be.

 

[Bperry]

Hello,

I recently purchased a home with a pool. Previously I had zero experience working with pools. We tried opening the pool ourselves and ended up with algae. Water was green and cloudy with noticeable algae floating on surface.

Couple weeks later, water is now crystal clear but we have brown spots scattered throughout the floor of the pool. When brushing it off it returns (not sure about if it returns to exact spot or not). And when vacuuming it to waste there seems to be an improvement but also seems to return in some places. Or I could just be missing spots. Sometimes they are so small that it is easy to miss at first glance.

After looking at stuff online it kind of sounds like yellow algae due to:
-Brushing causes it to poof up in a cloud
-It returns

But then these aren't happening:
-Doesn't appear to be on walls
-It is all over the pool not just in the more shady areas
-Water chemistry seems to be mostly fine and it is clear. We had high alkalinity that we got down and now pH is a smidge low.
-We are in the midwest and sounds like it is less common outside of the south.

I've tried touching it and seeing what it feels but it was just too hard to tell with 100% certainty because I have to go underwater (since it isn't on walls) and it immediately blows away when touched. There was one spot that maybe felt slimy but I think it felt gritty in other places.

I've tried asking a couple different pool stores about it and neither seemed concerned about it. Just mentioned vacuuming it out. If it is dirt/something that can be vacuumed out does it normally more than one go around?

We don't have a test kit yet but have been utilizing the pool store down the road. I understand that isn't ideal but here's the latest results from them:
FC: 3.86
TC: 3.97
CC: .1
pH: 7.1
Hardness: 197
Alkalinity: 146
CYA: 35
Copper: .3
Iron: .1
Phosphate: 1298

I'll attach some pictures. It is hard to pickup in photos but I'll post one and then another of same spot zoomed in. Would appreciate any suggestions on what it could be.

Hey welcome! Your chlorine is low if these tests happen to be right, and it’s unlikely they are. Pool store testing is really that bad…
Here’s a link to the chart explaining the chlorine level and why it’s balanced with CYA.

How are you chlorinating the water? Copper comes from products like algaecides and “blu” chlorine pucks that contain copper, which can cause problems when it builds up.

 

[Texas Splash]

Welcome! A good test kit do save you a lot of headaches and answer all of your questions. I suspect you have an algae problem, but a proper test kit is required for the SLAM Process and to perform an Overnight Chlorine Loss Test.

 

[evan567]

Hey welcome! Your chlorine is low if these tests happen to be right, and it’s unlikely they are. Pool store testing is really that bad…
Here’s a link to the chart explaining the chlorine level and why it’s balanced with CYA.

How are you chlorinating the water? Copper comes from products like algaecides and “blu” chlorine pucks that contain copper, which can cause problems when it builds up.

We are using Clorox Xtrablue via a floating feeder at the moment due to recommendation from a friend. But plan on switching to liquid soon because tablets increase CYA overtime, right?

We are flip flopping between two stores and the results have been fairly consistent. Not sure why they are bad/if they end up failing the same way that would produce the same wrong results but if not they are probably pretty accurate. When we were dealing with original algae issue they did say we had either high iron or copper. Can't remember which one it was.

 

[evan567]

Welcome! A good test kit do save you a lot of headaches and answer all of your questions. I suspect you have an algae problem, but a proper test kit is required for the SLAM Process and to perform an Overnight Chlorine Loss Test.

In between the switch from liquid to tablet (made the switch after original algae issue) we didn't chlorinate the pool for a few days and we were only seeing a drop of around 1.5 ppm per day which from what I read is pretty standard with chlorine. But yeah that's relying on possibly inaccurate store test and no overnight test. I'll need to order the kit.

 

[Bperry]

We are using Clorox Xtrablue via a floating feeder at the moment due to recommendation from a friend. But plan on switching to liquid soon because tablets increase CYA overtime, right?

We are flip flopping between two stores and the results have been fairly consistent. Not sure why they are bad/if they end up failing the same way that would produce the same wrong results but if not they are probably pretty accurate. When we were dealing with original algae issue they did say we had either high iron or copper. Can't remember which one it was.

Stop using those Clorox xtra blue tablets if you want to stop adding copper to your water. Do a search on the forum for pictures of what copper staining looks like. The pool store may try and sell you stuff with names like “copper out” or something similar but none of them actually gets copper out of the water. The stuff just sequesters it so it temporarily stops staining and making hair green. But it wears off eventually and so you have to keep buying more of it to keep it sequestered. Only way to get rid of copper is replacing the water.

The pool store isn’t intentionally bad per-se. The equipment they use needs to be cleaned, calibrated, regularly, and some of them hire seasonal employees who aren’t always trained very well. TFP has a specific process that needs consistent and accurate test results so the vast majority of users have been disappointed in the result accuracy or pool stores (and a few very expensive mistakes), and is why the recommendation to avoid them exists.

 

[evan567]

Stop using those Clorox xtra blue tablets if you want to stop adding copper to your water. Do a search on the forum for pictures of what copper staining looks like. The pool store may try and sell you stuff with names like “copper out” or something similar but none of them actually gets copper out of the water. The stuff just sequesters it so it temporarily stops staining and making hair green. But it wears off eventually and so you have to keep buying more of it to keep it sequestered. Only way to get rid of copper is replacing the water.

The pool store isn’t intentionally bad per-se. The equipment they use needs to be cleaned, calibrated, regularly, and some of them hire seasonal employees who aren’t always trained very well. TFP has a specific process that needs consistent and accurate test results so the vast majority of users have been disappointed in the result accuracy or pool stores (and a few very expensive mistakes), and is why the recommendation to avoid them exists.

There's definitely some similarities in a few photos. Do you know if copper stains puff into cloud when touched? I see mentions of it being hard to remove but I don't know if that means the stain is set in deep and requires scrubbing or if it means similar to what I'm facing and it comes back. Can't really find any good info on how it interacts when brushed.

 

[Bperry]

There's definitely some similarities in a few photos. Do you know if copper stains puff into cloud when touched? I see mentions of it being hard to remove but I don't know if that means the stain is set in deep and requires scrubbing or if it means similar to what I'm facing and it comes back. Can't really find any good info on how it interacts when brushed.

Copper stains (or any stains for that matter) don’t poof when brushed. Stuff that poofs is algae most of the time.

 

[evan567]

Posting here in case someone stumbles upon this:

I did more reading and found people with similar issues. Ultimately, ended up being an issue with their sand filter and another was the type of sand they used (zeolite). One suggested tying a sock to the return jet to temporarily prevent it. I haven't tried that myself but I did leave the pump off for 24 hours and I had no more spots.

So leaning toward either the filter or the type of sand being the issue. Unfortunately, I don't know what type is in it. I did read that adding diatomaceous earth, or even just topping off the sand, could also help.

I also noticed pollen floating on the surface. Wasn't a crazy amount but that may also be the issue as it is my understanding pollen is often mistaken as algae.

 

[PoolStored]

Zeolite is not sand. It is a sand substitute. Did you put zeo into your filter? I would be surprised, it is not a common practice.

My recommendation is that you get a proper test kit to diagnose your issue. Link-->Test Kits Compared

Given your symptoms I would lean toward algae, and filter problem second. When you get your kit, do this test. Link-->Overnight Chlorine Loss Test

 

[duraleigh]

What you see on your pool floor is dead algae. It continues to recurr because you have inadequate chlorine to keep it from re-growing.

If you continue to rely on the pool store, you will continue to get the same results.

I would encourage you to get one of the test kits we suggest and take control of your pool. I would start here..... Pool Care Basics Archives.

 

[Rachel B]

Hello,

I recently purchased a home with a pool. Previously I had zero experience working with pools. We tried opening the pool ourselves and ended up with algae. Water was green and cloudy with noticeable algae floating on surface.

Couple weeks later, water is now crystal clear but we have brown spots scattered throughout the floor of the pool. When brushing it off it returns (not sure about if it returns to exact spot or not). And when vacuuming it to waste there seems to be an improvement but also seems to return in some places. Or I could just be missing spots. Sometimes they are so small that it is easy to miss at first glance.

After looking at stuff online it kind of sounds like yellow algae due to:
-Brushing causes it to poof up in a cloud
-It returns

But then these aren't happening:
-Doesn't appear to be on walls
-It is all over the pool not just in the more shady areas
-Water chemistry seems to be mostly fine and it is clear. We had high alkalinity that we got down and now pH is a smidge low.
-We are in the midwest and sounds like it is less common outside of the south.

I've tried touching it and seeing what it feels but it was just too hard to tell with 100% certainty because I have to go underwater (since it isn't on walls) and it immediately blows away when touched. There was one spot that maybe felt slimy but I think it felt gritty in other places.

I've tried asking a couple different pool stores about it and neither seemed concerned about it. Just mentioned vacuuming it out. If it is dirt/something that can be vacuumed out does it normally more than one go around?

We don't have a test kit yet but have been utilizing the pool store down the road. I understand that isn't ideal but here's the latest results from them:
FC: 3.86
TC: 3.97
CC: .1
pH: 7.1
Hardness: 197
Alkalinity: 146
CYA: 35
Copper: .3
Iron: .1
Phosphate: 1298

I'll attach some pictures. It is hard to pickup in photos but I'll post one and then another of same spot zoomed in. Would appreciate any suggestions on what it could be.

I just posted a new thread… bc I, too, had brown spots on the floor of my pool, generally around the edges…

Was from my older son shooting the red Ryder BB gun in the back yard and some BBs falling in the pool… I just figured that out yesterday

Sounds like probably not your issue, but just in case you also have a BB gun + kids?

 

[Bperry]

I just posted a new thread… bc I, too, had brown spots on the floor of my pool, generally around the edges…

Was from my older son shooting the red Ryder BB gun in the back yard and some BBs falling in the pool… I just figured that out yesterday

Sounds like probably not your issue, but just in case you also have a BB gun + kids?

Switch him over to airsoft biodegradable bb’s. At least they won’t stain before your cleaner can pick them up.

 

[Rachel B]

Switch him over to airsoft biodegradable bb’s. At least they won’t stain before your cleaner can pick them up.

Eh, he’s 17yo… and I use the RRyder to deter bunnies etc that want to nibble things from my veggie garden… metal BB to the butt? Doesn’t hurt them but is a “go live somewhere else”… but I told my 17yo if I find any more in the pool? He’s fishing them out and putting the Vit C tabs on them… sure he will figure out how to not have to do that!

 

[evan567]

No BBs as far as I'm aware. Still haven't resolved the issue fully either. Not experiencing overnight light loss whenever I test it. Only seems to appear when filter is on. Slamming never gets rid of it fully. I caved and tried an algaecide and all it did was bleach them (they eventually turned back to their brown color).

I haven't messed with the filter at all so could still potentially be the issue. The only thing is the spots are all over, regardless of shade, but they do seem to appear in the same location after vacuuming/brushing. So not sure if it is pollen or something settling in the same spot because the water flow never changes or if it is algae. It meets the criteria but then at the same time doesn't. Kind of just over the pool at this point lol. Plus it's time to close so may just have to close it with the issue and hope it doesn't get bad over time if it is algae.

 

[duraleigh]

I suggest you decide whether to leave it for next Spring (sounds like it) or simply leave it now and close when the time comes. Clearing it up now will require a SLAM process. Doing the SLAM half-heartedly most always fails but you should choose one path or the other.

 

[evan567]

I was trying to SLAM one more time before closing. Only problem is liquid chlorine is non-existent around me now. I could make the jump to household bleach but yeah like you said I'm at the point where I need to decide to commit or not. Last time I was 2 weeks in SLAM with no success. That's a lot of bleach to buy lol.

 

[PoolStored]

Only problem is liquid chlorine is non-existent around me now.

Go to Menards website. Find the closest. Search for "liquid chlorine" Portage has 44 gallons. Didn't check the other stores.

 

[evan567]

Yep that's usually where I get it. I checked right after posting that and managed to snag some that popped up. The day prior they were out all over. Closest store that had some was an hour away.