Tenacious Yellow Everywhere

jfscottaz

Member
May 30, 2012
16
Tucson, AZ
After replastering pool seven years ago in this southwestern desert town, noticed an insidious, yellowing "bleed-through" this past year which is totally erasing all my bright white, relatively new marbleite. Something is taking over the entire smooth surface with no change in texture, like crusty calcium feel or something. Year round, I've kept chemical balance perfect (pH 7.4 avg; TA 80 ppm; chlorine within range and on the high side during swimming season, and regularly shocked; CYA in range; borate within range; phosphate <100), checked twice weekly, walls brushed weekly, and water drained when CYA goes too high. Some of us got nothin' ta do, right, but what is this stubborn, out-of-nowhere Crud? Last draining was about a month ago, and a stiff bristled nylon brush wouldn't do anything but 150-grit wet/dry sandpaper did the trick, took it all off with no change to plaster texture. I treated it with absorbic acid, nuthin'. Treated it for metals (Metalfree product), same thing. Algaecide treatment for the first time ever and ditto, nuthin'. This week I'm trying Phosfree for the first time ever even though phosphate level low, probably another waste. I haven't tried the dry acid in a sock trick, yet, because I want to know the cause of this phenomenon. As you know, an acid wash erases everything and it's starting to look like a complete wet sanding (polishing?) would be better anyway. Thoughts? Thanks...JS
 

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jfscottaz

Member
May 30, 2012
16
Tucson, AZ
It was ground up vitamin C tablets that I spread over the stains on steps when water was drained, nothing. Also did MetalFree treatment with CU-later bag in skimmer basket, no metals...JS
 

jfscottaz

Member
May 30, 2012
16
Tucson, AZ
Me thinks the Vitamin C tablets worked this time. Pics tomorrow. What's next? I'm thinking a few pounds of vitamin C are broadcast after bringing chlorine to 0 and lowering pH to 7.2 or so. Run pump 24/7 a few days and backwash DE filter, accordingly, in addition a adding another CU-lator bag. Thanks...JS
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,294
Laughlin, NV
To actually get the iron out, you should consider draining after the ascorbic acid treatment and start fresh. Sadly, the culator things really do not work all that well.
 

jfscottaz

Member
May 30, 2012
16
Tucson, AZ
Actually, my next step is to determine where the iron (rust) came from, right, probably from some rusted out galvanized pipe/coupling from its 1980 build used to fill the pool. That's a lot of rust to deposit into a 17K-gal pool over seven years (since new plaster), so I'm confident the villain piping will stand out and hopefully be a relatively easy homeowner repair. With swimming season six months away, I can probably deal with this crud then, assuming I find the rust culprit. I concur with your CU-lator opinion as the metal treatment I wasted my money on a few months ago (MetalFree bottle + CU-lator skimmer bag) was a definite bust. Thanks to you and James for helping this "experienced" pool owner out, being persistent with your stain prowess, and saving this guy lots more headache, frustration, and money...JS
 
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JamesW

TFP Expert
Mar 2, 2011
21,091
Note that all water has some iron.

There's no such thing as iron free water unless you run it through reverse osmosis or distillation or other process that's effective at removing iron.

Different supply sources have different amounts of iron, but none have zero iron.
 

Rattus Suffocatus

Silver Supporter
Jun 5, 2019
1,236
Corona de Tucson, AZ
So I need to ask. How are you getting your TA to 80 in Tucson? (Maybe the main system isn't as bad on TA as the Corona de Tucson system is. Dunno.) I've been struggling to get mine down to under 100 the whole season. I do need to work on better aeration though to bring pH back up when adding acid...winter project... just wondering. Good that the Ascorbic Acid is working for you... interesting to know this can happen in Tucson... I wasn't aware there was an issue with iron in the water here, but if an elephant was dissolved in our water it wouldn't surprise me...
 

jfscottaz

Member
May 30, 2012
16
Tucson, AZ
Note that all water has some iron.

There's no such thing as iron free water unless you run it through reverse osmosis or distillation or other process that's effective at removing iron.

Different supply sources have different amounts of iron, but none have zero iron.
Copy that but I just verified my badly rusted out plumbing. All are couplings, crosses, and stubs from the exposed copper main line, all hidden by house paint for 40 years. Fortunately, the long piping was copper and PVC so only these components were heavily rusted out. One of the ¾" galvanized stubs actually disintegrated during removal. Once I replace all with brass, I'll start on the iron removal. Thanks, again, guys! - JS
 

Rattus Suffocatus

Silver Supporter
Jun 5, 2019
1,236
Corona de Tucson, AZ
Good to know. Sorry to hear about the galvanized pieces... but as you did say, they can be replaced with copper and PVC.. good luck.... I am amazed at some of the stuff I see here.. definitely different than what I am used to growing up and spending most of my adult live in cold climates......
 

jfscottaz

Member
May 30, 2012
16
Tucson, AZ
So I need to ask. How are you getting your TA to 80 in Tucson? (Maybe the main system isn't as bad on TA as the Corona de Tucson system is. Dunno.) I've been struggling to get mine down to under 100 the whole season. I do need to work on better aeration though to bring pH back up when adding acid...winter project... just wondering. Good that the Ascorbic Acid is working for you... interesting to know this can happen in Tucson... I wasn't aware there was an issue with iron in the water here, but if an elephant was dissolved in our water it wouldn't surprise me...
Mr. Suffocatus, I learned those test strips, first of all, are not near as accurate as titration (drops). In fact, once I've used up my Taylor T100 kit, I'm going back to Ace Hardware-type 5-1 test kit (Chlorine/bromine, TA, pH, acid demand...read cheap here). It was nice pretending to be a hydrologist with the T100, but I pretty much know my pool now here at Houghton/22d. I'll use the 7-1 test strips to back up the drops, I guess, and check CYA. So, verifying TA with the drops is first thing for me, then pH and chlorine. I lower TA to 80ppm using only the 31.5% MA, no more that one pint each dose until 80 hit. Truthfully, if I overdo it with the MA and it goes lower, I don't care as pH always climbs here, y'know. I converted my pool to borate to stabilize pH, but before that had no TA problem using MA. Just make sure the other ranges are in check, like for TDS and CYA, sneaky trolls fer shore, Pard...JS
 

bryanq480

Well-known member
Jul 16, 2020
64
tempe, az
Mr. Suffocatus, I learned those test strips, first of all, are not near as accurate as titration (drops). In fact, once I've used up my Taylor T100 kit, I'm going back to Ace Hardware-type 5-1 test kit (Chlorine/bromine, TA, pH, acid demand...read cheap here). It was nice pretending to be a hydrologist with the T100, but I pretty much know my pool now here at Houghton/22d. I'll use the 7-1 test strips to back up the drops, I guess, and check CYA. So, verifying TA with the drops is first thing for me, then pH and chlorine. I lower TA to 80ppm using only the 31.5% MA, no more that one pint each dose until 80 hit. Truthfully, if I overdo it with the MA and it goes lower, I don't care as pH always climbs here, y'know. I converted my pool to borate to stabilize pH, but before that had no TA problem using MA. Just make sure the other ranges are in check, like for TDS and CYA, sneaky trolls fer shore, Pard...JS
high fill TA here in Tempe...was 150-160. Daily acid additions and i will be able to get in down to 80-100 in no time.