Can you name this stain? And what to do about it.

[nolefan]

I have had this pool at a rental house with the comfort that my local pool service has been keeping up with their end of our $75 per month contract. Boy was I surprised when my tenants moved out and I found that my SWCG had burnt up (but that's another story) and the service tech had been chlorinating by hand (not sure how or for how long). There was calcified material all over the spa waterfall tiles, and the bottom was filthy. After an enjoyable conversation with the pool service, I began to clean the mess.

I scraped the tiles and got them clean. Vacuumed and brushed the pool and washed the dirt out of the filter. I noticed these stains on the bottom of the pool and some on the steps. Were never there before and is the only part of the filth that I cannot clean no matter how much I brush it.

I let it run a bit then did a water test.

FC: 4
PH: 7.8 (or more as that is as high as my color goes)
CYA: 100 + ?
TA: 120
Salt: 1700

I was able to get a new SC-36 salt cell that day and got it replaced. Added 120lbs (3 bags) of salt, and 3.5 cups acid. Let it run for a few days.

Today's test:
FC: 5+ (highest I can test)
PH: 7.8
TA: 120
CYA: 100
Salt: 3100

I am in the process of adding acid to get the PH and TA down. Has a waterfall and SWCG for aeration. Not sure of the CYA measurement so keeping the FC as high as I can for now.

Any help identifying this stain and suggestions for removal would be greatly appreciated.

[attachment=2:jsj45m3j]Pool Stain 1M.JPG[/attachment:jsj45m3j]
[attachment=1:jsj45m3j]Pool Stain 2M.JPG[/attachment:jsj45m3j]
[attachment=0:jsj45m3j]Pool Stain 3M.JPG[/attachment:jsj45m3j]

 

[dmanb2b]

Sorry to hear :|

What is your CH level? That looks like more calcium scaling on the pool plaster surface

 

[nolefan]

That would be the only test I do not have at the moment. The stain is smooth to the touch though. The scaling was rough. It looks like a metal stain. But don't know how. I do have an electric heater on this pool. Not the one in my signature. Sorry.

Here now. Just did another set of tests.
FC: 6
PH: 7.8 still after 4 cups acid this morning
TA: 110 (went down 10 from this morning)

 

[jdp39]

Those are similar in color to the stains I'm trying to address although ours are not as severe and are a bit more streaky. Chemgeek suggested lowering PH as he has metal stains that evidently show up at higher levels. Alas mine are still there. Here's the other thread http://www.troublefreepool.com/is-i...o-become-imbedded-in-diamondbrite-t33014.html Still cking threads/info. Should I find a good way to identify will post here.
Good thread here as well http://www.troublefreepool.com/copper-stain-removal-off-plaster-t32612.html
Good luck!

 

[AussieLady]

I am not quite sure from your photo(s), but if your stains are "rust colored" patches then I can tell you from my own experience that problem occurs in my spa-ool, it is due to an imbalance of the pH and TA. My pebbletek finish "stains" whenever my alkalinity and pH are way off. As far as I know (and I'm still learning), alkalinity should be around 80 - 100 and pH should be around 7.6. If mine gets too far away from that, I end up with the rust colored patches. As soon as I get my pH and alkalinity back in line, within 24 - 48 hours the stains have disappeared. Not sure if this is helpful to you but thought I'd post just in case.

 

[nolefan]

I am not quite sure from your photo(s), but if your stains are "rust colored" patches then I can tell you from my own experience that problem occurs in my spa-ool, it is due to an imbalance of the pH and TA. My pebbletek finish "stains" whenever my alkalinity and pH are way off. As far as I know (and I'm still learning), alkalinity should be around 80 - 100 and pH should be around 7.6. If mine gets too far away from that, I end up with the rust colored patches. As soon as I get my pH and alkalinity back in line, within 24 - 48 hours the stains have disappeared. Not sure if this is helpful to you but thought I'd post just in case.

Thanks for the info. Actually, my TA and PH are both way off. TA is 120 and PH hasn't gone below 7.8 yet despite almost a gallon of acid over the past few days. This seems to be what is happening. I am planning on continuing to get the PH and TA down into normal ranges and with any luck I will have the same outcome. Let you know how it works out. Thanks again.

 

[dmanb2b]

Before adding more acid, lets confirm the PH reading...are you using a phenol red drop based PH test or strips? Longer term I'd suggest the TF100 from tftestkits.net or the taylor k2006 as great replacement kits

You can try holding a vitamin c tablet on the stain and see if it lifts...if it does, it's metal staining.

 

[nolefan]

OK, after all the advice and babysitting this pool daily, the stains are beginning to lift. I continued to lower the TA and finally got it in check. Today the stains were barely visible. Looks like it was the TA and PH after all. I did get the K2006 kit delivered today and my first test numbers were :

FC: 12 (on its way down from a shock)
CC: 0.5
PH: 7.6
TA: 80
CH: 240
CYA: 65

I was planning on lowering the TA to 70, but may just leave it alone at 80 and see how the stains go over a few more days. Thanks for all the advice.

 

[Richard320]

OK, after all the advice and babysitting this pool daily, the stains are beginning to lift. I continued to lower the TA and finally got it in check. Today the stains were barely visible. Looks like it was the TA and PH after all. I did get the K2006 kit delivered today and my first test numbers were :

FC: 12 (on its way down from a shock)
CC: 0.5
PH: 7.6
TA: 80
CH: 240
CYA: 65

I was planning on lowering the TA to 70, but may just leave it alone at 80 and see how the stains go over a few more days. Thanks for all the advice.

You're going to be kicking yourself for waiting so long to get a decent test kit! Just sayin'.

 

[nolefan]

Ok, so I'm Frustrated again. Rented the house again, and turned over the pool to a new pool company. They are actually the local service center for the SWCG that I have so I figured they would know how to care for such a pool. 4 days later, I went over there and found the stains were back, and now have multiplied around the pool.

[attachment=0:1ma6hxph]pool stain.JPG[/attachment:1ma6hxph]

A quick water test (K-2006) gave the following results:

FC: 2.5 (chlorinator was set too low, turned back up)
CC: 0.5
PH: 8.0+ (maxed out on chart, really deep purple)
TA: 100
CH: 210 (down from 220 four days prior, and down from 240 ten days prior)
CYA: 70
SALT: 3300

My question is.........since they seemed to lighten a good deal when the TA was at 70, then came back when pool company obviously added alkalinity after taking it over to bring it up to 100, and the fact my CH seems to be dropping off, are these stains calcium scale deposits? If so, what do I do? Will a TA of 60 or 70 for a while dissolve them? Or do I have to acid wash. The pool looks bad to me, but I do not have the ability to control it due to the fact its a rental. Pool company has to do it. Any suggestions?

 

[AussieLady]

If it was me, I'd just ask the pool service company to keep your pH and TA lower. That 8.0+ pH is often the culprit for the stains in my spa-ool. And I try to keep my TA around 80 - 90. Again, I'm no expert and can only share what is working for me. Good luck with the pool company!

 

[loop_pea]

I get iron staining around my pool from rusty grab rail brackets. It appeared when the pH was high after opening (because of a very high TA from the fill water), and started to lighten up when I got the pH down. I think the pH of 8.0+ could be your problem too.