Help with stain

[thelorib]

When we uncovered the pool there were some leaves in it due to a tear in the cover. The walls have staining and I have tried holding a chlorine puck to it as well as vitamin C tablets and neither seem to affect it anybody help diagnose this stain? I don't see an option to post pictures?

 

[Texas Splash]

For the pictures ... Have you tried linking your photos from Photobucket? That's what many of us do here on TFP. Upload your pics to Photobucket (free), then copy & paste the IMG code for that pic from Photobucket to your TFP post. Works great.

Also, you can try going to the bottom of your quick reply post where it says “Go Advanced”, and then down to where it says “Manage Attachments”. It may let you upload them that way. They may show-up large because you can't adjust the size of the attachment, but it may work.

As for the stains themselves ... no reaction to the tests huh? Might be good at this point to post a full set of test results from your TF-100 or Taylor K-2006. Perhaps that will give us some clue as to what may be happening.

 

[thelorib]

 

[pooldv]

That looks more like calcium scale. Check these articles to see if it helps to diagnose.

Diagnosing Pool Plaster Problems
Pool School - Calcium Scaling

 

[Texas Splash]

I agree! The pic tells a whole different story. Now would be a good time to post a full set of test results for us to see. Use your TF-100 or Taylor K-2006. That could help us confirm.

 

[thelorib]

Thank you, my test results are going to be off, I've been keeping the chlorine real high because I thought it was algae stain. My ph always runs high and I recently added muriatic acid. All other tests are always in normal range

 

[Texas Splash]

Well, if you allow the FC to drop to 9 or so just long enough to test pH and get a full set of results, it might be good at this point to confirm. Then you can immediately raise it again.

 

[thelorib]

Thanks for the links. Basically theres nothing I can do about the staining besides acid wash?

 

[Texas Splash]

If they are indeed from calcium, an acid wash may ultimately be required. But your current test results will help us with that as well to see what your current CSI reading is.

 

[thelorib]

ok thanks, the pool is only 3 yrs old...dont want to do an acid wash - hoping it will fade? Is it harmful? I need to do a better job at keeping the PH down. Will post test results later on

 

[thelorib]

Im reading about "no drain acid wash" Im wondering if adding a large dose of muriatic acid would fade all of this??

 

[Texas Splash]

You can try adjusting your pH and TA a bit lower and review the change it makes on the Poolmath Calculator's CSI row. Once you enter pH, TA, CH, and water temp, you can try to adjust those 3 items so that your CSI reading is slightly negative for a while in hopes that the negative CSI level will help dissolve/remove any existing scale. It's not an overnight process, in-fact it can take several months, but it doesn't really cost anything and it's worth a try. If you can scrub those areas form time to time that might help as well.

 

[pooldv]

Yes, a no drain acid wash is an option. The least invasive option is to keep your CSI negative, -0.4 to -0.5, and brush often. Over the course of a couple of months this should help. How much depends on how much scale is built up. If the stains are rough to the touch you can sand them with wet/dry sandpaper.

Going forward always maintain your CSI between -0.1 to -0.3 to prevent future scaling.

More here
Langelier and Calcite Saturation Indices (LSI and CSI)

 

[thelorib]

Is there a link to directions on a no drain acid wash?

 

[pooldv]

Not that I am aware of

Here is some info from OnBalance, resident plaster expert
A properly performed no drain acid wash works very well on dirt stains, recently deposited calcium scale, and iron stains. Recent copper staining might be removed, but older copper stains are more difficult to remove. The younger the plaster surface, the more easily stains are removed. Older pools are problematic in trying to remove the stains.*

An important issue is how much acid is being added. Too much acid added, then too much etching of the plaster surface which simply ages and makes the surface rougher and more prone to further staining. Calculate the amount of acid to reduce the TA to zero, and don't add any more than that.

On recently new plastered pools (less than one year) that have "gray discolorations" (and not stains such as from dirt, calcium, or iron), then no drain acid washes will not work. Gray mottling discoloration (due to improper troweling and materials) goes deep into the plaster surface and generally will not be removed, and only etches the surface in trying to remove them. That is not good for the pool.

These threads are pretty interesting
No Drain Acid Wash
No Drain Acid Wash - Success so far
No Drain Acid Wash

 

[thelorib]

Thank you!