Black lines from main drain

[bksbeat]

Our pool was resurfaced about 18 months ago. Everything has been great. A few months ago I have noticed these light black lines, on the bottom of the pool. They all seem to be originating from the main drain on the bottom of the pool, looks like a sold line and seem to run for about 4-5 feet. Don’t see these lines anywhere else in the pool. It is pretty light in color but it is there.I run a automatic cleaner nightly and the only thing I can come up with, logically, is the suction cleaner is sucking something out of the main drain and is causing these lines? Does this make sense and has anyone ever heard of this occurring.
Thanks,
Gary

 

[Rancho Cost-a-Lotta]

I'm not sure if anyone else will have any luck, but I can't see anything in the photos. As you're thinking this through, keep in mind the drain is the lowest point in the pool. It's more likely that whatever is causing the stains is starting on higher ground and moving down towards the drain. Take a look at the link below for identification help. Maybe try to take some pictures with different lighting conditions.

Stains in Your Pool

The stained pool is beyond embarrassing. Our in-depth Guide to remove stains in your pool will help you to remove the stains and prevent them in the future.

www.troublefreepool.com

 

[bksbeat]

The lines are there but I guess it is difficult in daylight with the glare. I will try and take more pic later when there is less glare and I can put the pool light on. Almost looks like half a spider web and everything is originating from the drain.

 

[Rancho Cost-a-Lotta]

How is your pool chlorinated?

 

[bksbeat]

I normally powder shock or liquid chlorine

The pool resurfacing was done in Apr 2002. We also had a heat pump installed with the resurfacing. I hope and pray I am wrong, but I hoping these are not rebar stains from the resurfacing. As I said I have only noticed about 6 months ago. It has not better or worse. Someone recommended using muraitic acid over the stains and doing a lot of brushing but these stains don’t seem to budge when I brush them.

 

[HermanTX]

The lines are there but I guess it is difficult in daylight with the glare. I will try and take more pic later when there is less glare and I can put the pool light on. Almost looks like half a spider web and everything is originating from the drain.

It is hard to see, maybe a night picture with lights on may help. It does appear you have an in floor cleaning system as I see 2 pop ups. Is that accurate?

 

[bksbeat]

Yes you are correct. It is auto suction cleaner that I have connected to the drain on the side of the pool and kicks on.when my pump comes on. I will take a pic later when it gets dark with the pool light on.

 

[BDY]

In for following

I have some of those same marks on my pool after it was newly plastered but i was told it was from water on the new plaster that pooled while it was filling (long story they has to replaster it the next day because they messed up). It was suggested on these forums to try sanding them once the summer season was over

There is one big splotch on the floor running to the drain and a few on the walls coming out of various ports.

(Ps - they tried an acid wash and it didn’t do a trying)

 

[BDY]

Here is the thread - the one difference is that mine showed up early while you say you were replastered 18 months ago. Any chance of just noticing them now?

New Pool Plaster Issues - PB debate

Hi all, Hoping I can get some insight into my plaster - pool is about 2 months old. It's an NPT Microfusion Stonescapes White plaster. I have been religiously using the TF100 kit since day 1, and managing Ph to below 8 every day (it goes down to 7.6 and then raises to 8.0 or 8.1, and I add...

www.troublefreepool.com

 

[Rancho Cost-a-Lotta]

Rebar rust stains are normally much more pronounced.

Try ascorbic acid (vitamin C) on the stains as recommended in the Wiki article.

Have you used any products containing copper? Pool RX? Any products with the word minerals?

Do you have a heater?

What type of powder shock do you use? How do you put it in the pool.

Post a full set of test results.

Have the pool store test your water. We are only interested in the results for metals (iron/copper).

 

[bksbeat]

I did just speak to the company that did the resurfacing. He does not believe it is rebar stains. I did run a chemical test and my ph level was high so I just went to the pool store and got some muraitic acid (the company thinks the stains have something to do with high ph level?) so I just put a gallon of acid over the stains and did some brushing but those stains are not improving. Now, it is not dark stains and I can probably live with it as long as it does not get worse or escalate across the pool. As I said it seems very centralized around the main drain on the bottom of the pool. Re. Chemicals I either use liquid chlorine from my pool store or super pool shock from that company “ in the swim “ online. Now that I think about it, I have primarily been using the shock the last few months?Could that cause an issue?

Yes, I got a heat pump with the resurface 18 months. The company that did the resurface did mention to me today to take precautions with the heater and other metal equipment -not exactly sure what they mean and what precautions I am suppose to take with the heat pump ? How exactly can be the heat pump cause something like this? I understand we don’t want he metal/corrosion coming thru the water but this is a brand new heat pump?

 

[Rancho Cost-a-Lotta]

super pool shock from that company “ in the swim “

This is calcium hypochlorite and other undisclosed ingredients. Over use can result in scaling issues.

With the amount of money you spent on resurfacing and equipment, it would be worth your time to invest in a recommended test kit. We need a full set of reliable test results. Take a look at the test kits at TFtestkits.net. The TFPro kit is the best value.

Follow the directions in Post 10.

@JamesW is great with stains, but there may not be enough info to comment on at this point.

 

[bksbeat]

Thank you Rancho. Where I am mystified is how can these lines/stains be so structured. I will take a pic in an hour or so when it gets dark. It almost looks like a spider web all originating from the main drain. I do have a test kit, I will run some tests.
I just tested the ph level. Now it very low. It was high this morning before I put the acid in which this pool company recommended to put 3 gallons in to help with the stains? I only put 1 gallon in and now it is around 6.8.
I’m not sure how I test for metals ? It is a pool master kit that tests for chlorine/bromine/ph/acid demand and total alkalinity

Total alkalinity is 80 ppm
I added some ph up but ph is still low. Will add some more ph up
Chlorine level is about 3
Ph level is about 7.2?

 

[bksbeat]

Here is the thread - the one difference is that mine showed up early while you say you were replastered 18 months ago. Any chance of just noticing them now?

New Pool Plaster Issues - PB debate

Hi all, Hoping I can get some insight into my plaster - pool is about 2 months old. It's an NPT Microfusion Stonescapes White plaster. I have been religiously using the TF100 kit since day 1, and managing Ph to below 8 every day (it goes down to 7.6 and then raises to 8.0 or 8.1, and I add...

www.troublefreepool.com

There was definitely nothing for at least 6 months after the resurface. I think initially they may have just been 1 or 2 streaks now their are about 4 or 5. They are light so some people would not even notice if you were not aware of it. I will take some updated pics in a few minutes when it get darker. I took a video which shows it well, then realized I cannot upload a video on this app.

 

[HermanTX]

There was definitely nothing for at least 6 months after the resurface. I think initially they may have just been 1 or 2 streaks now their are about 4 or 5. They are light so some people would not even notice if you were not aware of it. I will take some updated pics in a few minutes when it get darker. I took a video which shows it well, then realized I cannot upload a video on this app.

Load the video to YouTube, then copy the link on teh thread.

 

[bksbeat]

Video of pool stains/lines

 

[Rancho Cost-a-Lotta]

Do the black lines run to your pool returns?

 

[bksbeat]

No, they run from or near the main drain for about 4 or 5 feet but they not on the walls where the returns are. The pool company that did the resurfacing are coming out today to have a look. They had recommended to put 3 gallons of acid and brush and brush. I put one gallon of acid in the pool with some ph up and although nothing budged when I brushed, it definitely looked much better this morning after I ran the pump most of the night. The stains were much lighter, and yes, another 2 gallons of acid may well get rid of the stains but I am more interested in what caused this and to ensure it does not happen again. They think it is related to the chemicals I am putting in the pool but I have had the pool for 15 years and never had these structured lines/stains before, even before the pool was resurfaced. I will let you know what they say

 

[Rancho Cost-a-Lotta]

You'll need the test kit. Get water tested for metals at the pool store.

 

[Rancho Cost-a-Lotta]

I would open up the filter and see if the color of the cartridge looks normal.