Please help with stains

[faid2black]

Hi everyone, i have just acquired a pool and am trying to get an understanding of everything going on with it. The surface has been replastered fairly recently (about a year or so old) and has some staining going on. The stains are dull in color... grey/black. They are most visible in shade/indirect light, and they do not brush off with a nylon brush nor vacuum away. The water is really cold right now, but i tried to reach down as far as i could to rub against the plaster and it doesn't really feel slimy to me. The walls appear to have a more solid stain than the floor does. It looks to me as though someone tried rubbing something on the floor stains in some areas and cleaned it up some... but maybe that's just how the stain developed? I'd appreciate any input i can get on hopefully addressing this.

Here are two pictures on my flickr that hopefully show enough of what's going on... these were from before vacuuming but that didn't change the ugliness...

1.

IMG_0799 by faid2black, on Flickr

2.

IMG_0798 by faid2black, on Flickr

Thanks for any and all help!!!

 

[susa]

post full test results

 

[faid2black]

Ah, forgot to post those. I'm trying to remember off the top of my head, the results from over the weekend. I can confirm these later on...

FC=4
CC=5
BR=8
PH=7.4
TA=100
CH=250
CYA=100

Also, if this affects things, a lot of the pool is not getting much direct sunlight right now.

 

[JasonLion]

If those test results are correct, it looks like you have several problems. You really don't want CC to ever be above 0.5. If the CC test result is correct you need to shock the pool. Likewise, CYA at 100 is too high. Worse, the CYA test will often show 100 when the actual level is higher than 100. How are you doing your water testing?

There are a couple of possibilities for what might be causing the stains, some minor, some fairly problematic. As a first step, I suggest holding a trichlor tablet against a stained area for a minute or two and checking to see if that does anything. Also, check around and see if the former owner left any chemicals around, and if so tell us what you find.

 

[faid2black]

Oh, i'm sorry, i screwed up on the CC number. I believe CC was 1, and the TC was then 5. Even having CC at 1, it sounds like i need to shock. We are using a taylor test kit we got from a local pool store... not sure what model but it was the best one they had...

I was concerned about the CYA, but it seemed so subjective with seeing the black dot... my wife and I kept asking each other is it gone yet? is it gone yet? so we just kept adding drops. Maybe we should redo that one.

Unfortunately, the previous owner of the house left us nothing for the pool, except for a bag of DE. We're starting from scratch with everything =(

 

[chem geek]

I was concerned about the CYA, but it seemed so subjective with seeing the black dot... my wife and I kept asking each other is it gone yet? is it gone yet? so we just kept adding drops. Maybe we should redo that one.

Note that the CYA test goes backwards in numbers. The scale is at 100 near the bottom of the tube and its 30 or 20 near the top. So for 100 that means the black dot disappears rather early while if the CYA is low then you'll nearly fill up the tube and maybe still see the black dot. I just want to make sure you are doing this correctly.

 

[faid2black]

U know, my wife really wanted to do the testing. She did great, but had trouble with the cya. I know I was still able to see the black dot for sure, though it was getting faint. I will retest the cya tomorrow and ill post what I find.

 

[Richard320]

U know, my wife really wanted to do the testing. She did great, but had trouble with the cya. I know I was still able to see the black dot for sure, though it was getting faint. I will retest the cya tomorrow and ill post what I find.

Here's a tip: repeat the test several times. Mix it up good, hold the viewtube down about waist high and slowly dribble the sample in. I find myself holding the tube with my whole hand, which blocks a lot of light. Hold it near the top with thumb and forefinger for best results. Take your reading, then pour it back into the mixing bottle and mix it up some more, then repeat. It takes practice; don't be ashamed or upset that you have to repeat it 8 or 10 times until you get the same number twice.

 

[faid2black]

thanks for the advice, i'll give this a shot soon =)

 

[faid2black]

So I confirmed, after testing a few times, it looks like cya is about 90-100.