Is the vitamin C test 100% reliable, meaning that if the stain clears it can only be a metal stain?
confirmation of metal stains
- Thread starter RRJohnson
- Start date
Welcome to TFP!
The vitamin C test is reliable when determining if a stain is metal or organic. Because vitamin C is an acidic substance, it readily attacks metals that have deposited themselves on a surface. If a stain lightens after being exposed to vitamin, it is a metal.
When it comes to stains, they are the result of either organic debris or metals that are precipitating out of solution. The tablet test makes it easy to determine which one is the culprit.
The vitamin C test is reliable when determining if a stain is metal or organic. Because vitamin C is an acidic substance, it readily attacks metals that have deposited themselves on a surface. If a stain lightens after being exposed to vitamin, it is a metal.
When it comes to stains, they are the result of either organic debris or metals that are precipitating out of solution. The tablet test makes it easy to determine which one is the culprit.
Thank you. I just needed to confirm that. We have battled what we believe to be metals all summer. EVERY 5 days the pool will pull the stain again. We have a SWG, 20,000 vinyl pool. I can't even count how many bottles of every type of metal sequestrant, and stain remover we have used. We cut the heater out last month; put in new sand 2 weeks ago to make sure the filter wasn't contaminated; last Thursday we finally drained down to 12 inches in the shallow end, refilled, drained again to 6 inches, refilled, balanced and the water was perfect on Sunday (I'm afraid to even see the water bill). Last night, we noticed the stain starting to come in again. We are at a loss on where the metal is coming from. Our only thought is that is may be the ladder. It does have a tiny bit of rust around the bottom feet. We tried to remove it last month but couldn't get it out..it won't budge. In the attempts however, the rubber feet came off the bottom and tons of nasty brown water came out. (we have since treated and cleaned the water in addition to draining last weekend). In your opinion, do you think the ladder is causing the metal problem? My next try is to call a professional to come out and replace it....
Identifying the issue by remote control (which is what is done on the forum) has to begin and end with water test results. Read "The ABC's of Pool Water Chemistry" up in Pool school and then post test results for....
pH
FC
CC
TA
CH
CYA
From there we can start to diagnose what's up with your pool. Until then, everything is just wild guesses.
pH
FC
CC
TA
CH
CYA
From there we can start to diagnose what's up with your pool. Until then, everything is just wild guesses.
What is your fill water -well or municipal? Has your fill water been tested for metals?
Fill water is municipal; yes it was tested and clean.
Last night at 8:00pm
pH - 7.5
FC - 5+
TC - 5+
TA - 70
CH - 140
CYA - 75
Salt - 3200
We have Leslie's test kit, and just read how to test FC over 5, so we will be doing that this evening. After the reading last night, we decided to get the FC up to shock level at 20ppm in case it was an algae stain.. there is a very very small amount of dust particles on the steps and hottub (both are white so you can see it there), and we thought maybe mustard algae. The tablet test definitely point to metals though...
Also.. another thought, our salt cell is Hayward Aqua cell T-15, and it is 6 years old.. we had it tested 2 weeks ago and it showed that it is still working...
Last night at 8:00pm
pH - 7.5
FC - 5+
TC - 5+
TA - 70
CH - 140
CYA - 75
Salt - 3200
We have Leslie's test kit, and just read how to test FC over 5, so we will be doing that this evening. After the reading last night, we decided to get the FC up to shock level at 20ppm in case it was an algae stain.. there is a very very small amount of dust particles on the steps and hottub (both are white so you can see it there), and we thought maybe mustard algae. The tablet test definitely point to metals though...
Also.. another thought, our salt cell is Hayward Aqua cell T-15, and it is 6 years old.. we had it tested 2 weeks ago and it showed that it is still working...
Given your pH, TA and CH levels and your fill source, nothing would indicate there is metal in your pool water.
I would get a different test....don't know what the tablet test is that you used but I don't see anything (other than that test) that would indicate to me you have ametals issue.
I would get a different test....don't know what the tablet test is that you used but I don't see anything (other than that test) that would indicate to me you have ametals issue.
We use Leslie's Stain Remover - Ascorbic Acid and will completely removed stains. We did have it tested by Leslie's on Saturday after the fresh fill it was perfectly clear - they tested it FC 3/CYA 30 which I think is typical for the municipal water. It also tested 0 on the metals We wanted to raise it to the SWG recommendations on this forum so we added bleach and conditioner to get it to the above readings - which I think is balanced now. We also added 1/2 bottle of Jacks Magic Magenta Stuff just in case it was pulled metals from the ladder to keep them sequestered.
I'll try to get some new pictures tonight, so you can see it is starting again in the hottub. I do have some pictures from last Thursday BEFORE we drained/refilled. This happened within a 2 day timespan, and the water was so out of balance from everything we had tried at that point, that we decided to drain.
I'll try to get some new pictures tonight, so you can see it is starting again in the hottub. I do have some pictures from last Thursday BEFORE we drained/refilled. This happened within a 2 day timespan, and the water was so out of balance from everything we had tried at that point, that we decided to drain.
You may already know this, but when you use ascorbic acid, whether it's pool store type or from a chemist shop, it is suggested you drop chlorine levels to zero (it eats chlorine anyway). Then you bring the chlorine up very veeeeeery slowly to prevent the stain from re-forming -- and expect that the process of the AA will CONTINUE to eat your chlorine at a higher rate than you expect. Eg. if you just go right back to full chlorine in a few days, or if you don't have a FULL dose of Jack's Pink/Magenta whatever (meaning 2 bottles, not one, if your pool is in the neighborhood of 20,000 gallons), in about a week or two, you might see the stain re-form, IME. If your PH raises quickly, you may also see stain reform.
In other words, if it is actually a metal stain, eg. iron, you will need to come back from stain treatment very slowly, can't shock for at least 2 weeks, will always want to keep your ph on the lower end and will need to absolutely MAINTAIN an effective PPM of sequestrate (eg. Jack's) via weekly additions of sequestrate. It kind of sucks
Now, I have well water, so I'm stuck with this for the moment. In your shoes, if you know no fill has ever been metal contaminated, I might try a new ladder (not that expensive) and also check your light for corrosion. Did you at any point use pucks? Sometimes they park and corrode things.
If you'd like to hear other's experiences about the way to remove stains through a full AA treatment, use the search bar -- there's lots of threads. That might help. However, you'd usually want your own drop kit to be testing while you're working on these kinds of issues.
The pool store's metal detection sampler also SAYS MY POOL has no metal but guess what - it's WRONG -- my fill has .5 ppm iron -- in the pool, it is just sequestered, so doesn't read, but precipitates if the ph drifts too high.
Aquarium stores, btw, sell iron test kits. But a FAS/DPD kit for the rest of your chem would be a better first investment, IMHO. Good luck!
In other words, if it is actually a metal stain, eg. iron, you will need to come back from stain treatment very slowly, can't shock for at least 2 weeks, will always want to keep your ph on the lower end and will need to absolutely MAINTAIN an effective PPM of sequestrate (eg. Jack's) via weekly additions of sequestrate. It kind of sucks
Now, I have well water, so I'm stuck with this for the moment. In your shoes, if you know no fill has ever been metal contaminated, I might try a new ladder (not that expensive) and also check your light for corrosion. Did you at any point use pucks? Sometimes they park and corrode things.
If you'd like to hear other's experiences about the way to remove stains through a full AA treatment, use the search bar -- there's lots of threads. That might help. However, you'd usually want your own drop kit to be testing while you're working on these kinds of issues.
The pool store's metal detection sampler also SAYS MY POOL has no metal but guess what - it's WRONG -- my fill has .5 ppm iron -- in the pool, it is just sequestered, so doesn't read, but precipitates if the ph drifts too high.
Aquarium stores, btw, sell iron test kits. But a FAS/DPD kit for the rest of your chem would be a better first investment, IMHO. Good luck!
That is good information. I did read alot of that, and many other things. I assumed that we got rid of the AA with the metals when we drained the pool, and that we could go right back up to recommended FC and PH. What exact levels would you recommend for SWG with known metals? I'll try to get them at that level and add more Jacks magic.
Hmm, that should have been true, since the "ultimate" fix is to drain and refill! Egads. That would suggest either that something is either in your fill water and is undetected by pool store; or iron is blowing in from fertilizer, or something is somehow corroding and getting to the water.
Does the stain look like iron/faintly yellowish/rust-colored?
If it were, the Jack's Magic will tell you proper initial dose (eg. for Pink, which is for iron, it's 1 32 oz bottle per 10k gallons, so in your case would be 2, but don't know about the SWG version of Jack's.) JM prefers you buy their test kid to test ppm. I just add 16 oz. every week to maintain - stains don't seem to get worse, but also have not gone away either (as I don't want to do AA treatment and thereby close the pool to swimming until the fall when it's cooler.)
If you mean how low/slow for SWG when bringing back from AA treatment, I'll defer to someone with a little more direct AA + SWG experience. This is my first year with pool and while I was forced to learn a lot under duress (foreclosure pool) I am not certain the ideal parameters for SWG.
I believe one of the super poster/mods such as Chem Geek or Richard had told me to keep ph around 7.2ish for a few weeks and take at least a week getting back up to recc FC.
Does the stain look like iron/faintly yellowish/rust-colored?
If it were, the Jack's Magic will tell you proper initial dose (eg. for Pink, which is for iron, it's 1 32 oz bottle per 10k gallons, so in your case would be 2, but don't know about the SWG version of Jack's.) JM prefers you buy their test kid to test ppm. I just add 16 oz. every week to maintain - stains don't seem to get worse, but also have not gone away either (as I don't want to do AA treatment and thereby close the pool to swimming until the fall when it's cooler.)
If you mean how low/slow for SWG when bringing back from AA treatment, I'll defer to someone with a little more direct AA + SWG experience. This is my first year with pool and while I was forced to learn a lot under duress (foreclosure pool) I am not certain the ideal parameters for SWG.
I believe one of the super poster/mods such as Chem Geek or Richard had told me to keep ph around 7.2ish for a few weeks and take at least a week getting back up to recc FC.
The pool levels are the same this morning as posted above.
Here are some pictures of what the water looks like now as the stain returns...[attachment=0:1agtg36i]Photo Jul 25, 4 57 07 PM.jpg[/attachment:1agtg36i][attachment=1:1agtg36i]Photo Jul 25, 4 57 11 PM.jpg[/attachment:1agtg36i]
Here are some pictures of what the water looks like now as the stain returns...[attachment=0:1agtg36i]Photo Jul 25, 4 57 07 PM.jpg[/attachment:1agtg36i][attachment=1:1agtg36i]Photo Jul 25, 4 57 11 PM.jpg[/attachment:1agtg36i]
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Well, I'm assuming that circle in the hot tub is where you put a sock of AA...which certainly would suggest metals. I have never lived through algae (yet, and hoping to keep it that way) so I hope other posters with more experience look at your pics as well (we all tend to see that which we know, right?!). However, I've usually seen it written that if the water looks CLEAR but greenish tint it usually means metal, which combined with blue liner, looks greenish. Your water looks pretty clear from the picture...but tinted.
I can't work out how it's getting there, but maybe you have copper precipitating? I only say that because in the hot tub, the stain is a little darker in tone than my yellow/brown/tan/rust iron stains...but it could be the shadow.
Did you ever use an algacide with copper? Do you know your CSI index (I am vinyl, and not salt, so I don't know a lot about that index, but believe there's reference in Pool School). Also, somewhere on another thread, a person with SWG was contemplating whether it was possible that a small level of current from an improperly bonded pool area combined with low voltage lights may have been exacerbating corrosion that was resulting in metals in the water. The complexity of that situation is way above my present experience level, but have you installed anything new this year or had other electrical work done?
I realize I am asking more questions and have no answers...hopefully someone can give an informed set of things to check. I would likely consider a FULL dose (you said you used a half bottle of jack's -- normally a FULL does starts with a full bottle per 10,000 gallons -- I don't see pool specs in your signature, so I can't tell if you're under-dosing or not.)
I can't work out how it's getting there, but maybe you have copper precipitating? I only say that because in the hot tub, the stain is a little darker in tone than my yellow/brown/tan/rust iron stains...but it could be the shadow.
Did you ever use an algacide with copper? Do you know your CSI index (I am vinyl, and not salt, so I don't know a lot about that index, but believe there's reference in Pool School). Also, somewhere on another thread, a person with SWG was contemplating whether it was possible that a small level of current from an improperly bonded pool area combined with low voltage lights may have been exacerbating corrosion that was resulting in metals in the water. The complexity of that situation is way above my present experience level, but have you installed anything new this year or had other electrical work done?
I realize I am asking more questions and have no answers...hopefully someone can give an informed set of things to check. I would likely consider a FULL dose (you said you used a half bottle of jack's -- normally a FULL does starts with a full bottle per 10,000 gallons -- I don't see pool specs in your signature, so I can't tell if you're under-dosing or not.)
Yes, I was just looking at another thread on pool bonding and something about a copper wire on the SWG. We did have to repair the motor this year. If it wasn't properly bonded, I guess that could cause issues. I'll look and see if the bond wires seem to be in place. Has anyone heard of an Anti-Electrolysis Zinc Anode? They come in a variety of sizes, and aren't that much... should I try one?
I added a full bottle of Metal Free (from Leslie's, the only brand I could get to) last night. These are readings this morning (from Leslie's) I'll check them with my own kit this evening.
FC 10ish
PH 7.4
TA 90
CYA 50 - something seems to be lowering this, but I'll double-check the reading this evening
CH 150
No copper
Salt 3700 - not what my SWG reading display is, so I'm not sure this is correct
Stains look about the same this morning.
FC 10ish
PH 7.4
TA 90
CYA 50 - something seems to be lowering this, but I'll double-check the reading this evening
CH 150
No copper
Salt 3700 - not what my SWG reading display is, so I'm not sure this is correct
Stains look about the same this morning.
Stains are getting worse today, even with a full dose of sequestrant. I've found this article on pool bonding which indicates improper bonding would cause metal stains, and checked my equipment (the ring around my pool light is discolored but not black). I have a bonding wire coming from the ground to the pump bonding lug, and over to the heater bonding lug. There is a bonding lug on the bottom of the SWG control panel, but no wire is hooked to it. Would this cause the metal staining?
RR, maybe if you post a new post with the question about the bond wire and swg the folks familiar with same will see the thread and respond. I just read that article and a few other pool tech articles/comments around the web, and your theory Has logical appeal to me, particularly since something has changed this year and you're having stains this year (and presumably did not in the past.)
At this point, if you've confirmed the stain is metal, further shocking or other forms of oxidization will exacerbate the staining as I understand it. If you wanted to further confirm the nature of the staining, you might consider ordering jack's magic stain test kit.
If you tested fill water yourself (it sounded like you had leslie's do it?if you haven't yet invested in your own fas/dpd kit, you may want to, plus possibly copper and iron test kits) etc., and if you have fresh water, and full sequestate and you haven't fertilized nearby soil for wind born metal contamination, and it's inorganic, then that pretty much leaves us with some kind of system-component-erosion phenom, which sounds like it could be
related to bonding. But I am puzzling along with you
Hopefully someone will come along and contribute, but maybe the fresh heading about bonding/swg and stain might net you someone with experience!
At this point, if you've confirmed the stain is metal, further shocking or other forms of oxidization will exacerbate the staining as I understand it. If you wanted to further confirm the nature of the staining, you might consider ordering jack's magic stain test kit.
If you tested fill water yourself (it sounded like you had leslie's do it?if you haven't yet invested in your own fas/dpd kit, you may want to, plus possibly copper and iron test kits) etc., and if you have fresh water, and full sequestate and you haven't fertilized nearby soil for wind born metal contamination, and it's inorganic, then that pretty much leaves us with some kind of system-component-erosion phenom, which sounds like it could be
related to bonding. But I am puzzling along with you
Hopefully someone will come along and contribute, but maybe the fresh heading about bonding/swg and stain might net you someone with experience!
Update: We called in a professional pool company to analyze the water, and they found extremely high levels of phosphates (remember I had just drained/refilled one week prior to this). They said the phosphates were well over 3000, and had seen two other cases where phosphates this high would stain pools. They recommended PhosFree. At the same time, as a pre-caution, we did notice the SWG control panel was not in the bonding loop, and we attached the copper wire to the bonding lug on the unit. We used one 3L bottle of PhosFree, and within a day we saw a brown substance starting to floc together. After 2 days, we backwashed (very brown water), then vacuumed the floc'd up areas to waste, and noticed the pool wasn't as stained. We added more water (because we had vacuumed out quite a bit), then treated again with another 3L bottle of phosfree and waited 2 days, backwashed and vacuumed to waste. After 1 week, the stain is completely gone! I've never seen anything but ascorbic acid remove the stain, and we are, to say the least, shocked and ecstatic! We still have over 1000 phosphate level, but are now without stain! Our next step is to use the Phos Floc (which is made for levels over 1000) to try and get more of the phosphates out. We would probably have used this initially but couldn't get it locally so we had to order it online. Will keep you posted!
While I can't speak authoritatively on the precise chemical reactions involved above, I am convinced that the phosphates nor the bonding had nothing to do with your pool clearing.
A much more plausible explanation is you had algae and organic staining in your pool and sufficient chlorine and vacuuming and cleaning your filter finally cleared it. There is nothing in this or any other forum over the last eight years that would support the removal of metal stains by a phosphate reduction or by bonding an SWG.
A much more plausible explanation is you had algae and organic staining in your pool and sufficient chlorine and vacuuming and cleaning your filter finally cleared it. There is nothing in this or any other forum over the last eight years that would support the removal of metal stains by a phosphate reduction or by bonding an SWG.
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