IRON STAINING- Vitamin C tabs in filter?

[Donna P]

Hi all. I’ve been following any and all protocols to remove and sequester iron staining but it still (randomly) re-appears. All levels have remained pretty much within normal range (except For calcium- I did a stick test on the house water, it’s over 500 ). I’m no pedologist, but I think I’ve determined that because there is high iron content in the desert dirt & dust (anyone heard of “Red” Rock Canyon?) and we get nasty wind storms in Vegas, the staining may be due to the dirt blowing around outside & landing in the pool. I’ve noticed the staining comes back with a vengeance after major winds.
SO.... I’ve accepted that AA treatments and metal sequestrants are probably going to be part of my normal maintenance routine.

Anyone know of any reason why I shouldn’t put a few vitamin C tablets in a floater/ filter/ chlorine dispenser to help maintain cleanliness (NOT as a replacement for full treatments ) while still adding a sequestrant weekly?
Thanks.

 

[jtpipkin]

vitamin c cancels chlorine - won't work in small doses but may cause an issue with sanitation

 

[AndyTN]

Could the dust storms possibly be causing the pH to rise? If iron is in the water, the higher the pH the more likely Metals will precipitate causing the stains.

Just using a little bit ascorbic acid will not be effective because the chlorine will just counteract it. Using a little bit is only good for spot treatments. My fiberglass steps will show iron staining before my liner and I will put vitamin C tablets in a sock to spot treat the steps.

What are you using to actually remove the iron from the water? With you already having staining, I don't think the sequestrant is going to be a long-term solution. Have you tried using polyfill to help absorb some of the iron in the water? I'm sure your water bill in Nevada is expensive so I would try some of the proven methods before suggesting a water Exchange.

 

[Donna P]

I thought that the presence of chlorine only weakened the effectiveness of the AA, not the other way around...?

i started keeping a pool chemical test ‘diary’ to see if there were any similarities when the staining appears (it’s random) and Ironically enough, no, the PH has remained pretty consistent around the 7.2-7.4 range, although last week it dipped below 7.0 (I was out of town). I haven’t tried polyfill, but I do have a skimmer ’sock’ and was using a CuLator in the filter, but it’s been a few months since I replaced it (those suckers are expensive!).

My water bill is nothing compared to most- I live alone, don’t have to water any grass and don’t shampoo my hair nearly as much these days because I’ve been forced into covid exile and don’t go anywhere
*sigh* I‘ll continue to pay attention to the weather & see what happens. Thanks!

 

[Texas Splash]

anyone heard of “Red” Rock Canyon?

Why of course! Donna, I'm a Vegas native - basically raised there until I joined the service. But in all my TFP days, I don't recall anyone from the Vegas valley having iron problems either from the local reservoir supply or surrounding areas. It gets crazy windy, I'll give you that, but not so sure RR or any other area is the prime contributor. So to be sure, I wanted to go back to a couple basics to ensure we aren't chasing the wrong Jackalope (ha ha):

- You've hinted to a couple test numbers that caught my eye. The low pH along with a heater being one of them. I'm wondering if the staining might be copper from the heater element?
- Can you post a fresh set of full test results from your K-2006?
- Are you still relying on that tab dispenser (primarily) for your daily chlorination?
- Have you added anything else to the water other than tabs and the sequestrant? Any other pool store products?
- The staining you are speaking of, can you post a pic of it? Also, did you already try rubbing a Vitamin C tablet on those stains to confirm it worked?

I have a gut feeling something else may be causing your staining, but the additional info may help confirm.

 

[Donna P]

Hi Pat!
Thanks for responding.
- You've hinted to a couple test numbers that caught my eye. The low pH along with a heater being one of them. I'm wondering if the staining might be copper from the heater element?
It's possible, but this staining issue didn't really start until I had the pool for about 9 months. Nothing should be corroded, everything was installed new in April, 2019. If it IS the heater, there's not much I can do except see if the filtration process is able to bypass the heater, right?

- Can you post a fresh set of full test results from your K-2006?
Today:
TC/FC- already under 1 ppm today (It's over 100 degrees every day). I like to keep it around 4ppm because it seems to also stain sometimes when it gets much over that. I put 25-30 oz of liquid chlorine in it every night (which is more than the pool math calculator suggests, mind you) in addition to a tab in the chlorine dispenser AND a tab in a floater. I am burning through chlorine like crazy, but fortunately the pool stays crystal clear
PH= 7.2
Alk=100
I brought these up to recommended levels about 10 days ago, but obviously they dropped back down.
CAL- I think this one is a lost cause. It's over 1000ppm & always has been, even after a partial drain...... Vegas water
Now I'm seeing (hard) calcium build up at the water line. Good grief.
CYA- 40

- Have you added anything else to the water other than tabs and the sequestrant? Any other pool store products?
I use Baking Soda for ALK, and that along with aeration seems to bring up the PH also (but I do have Bioguard/sodium carbinate if baking soda doesnt work for PH). I've rarely had to bring DOWN Alk or PH.
I've used Jack Magic in the past but I'm now using 6 oz Proteam Metal Magic about every 2 weeks.

- The staining you are speaking of, can you post a pic of it? Also, did you already try rubbing a Vitamin C tablet on those stains to confirm it worked?
Yes, vitamin C clears up the staining. I use Bulk Supplements powder to treat it. Attached is a pic of the beginning stages of staining, you might need to zoom in a bit; it's all below the water line.
Again, it seems to appear after strong winds... but I'll try any suggestions.

 

[Texas Splash]

Well shoot. If Vitamin C removes the stain, it's iron. So weird. Maybe I'll try to pull up a Vegas Water District water report. In the meantime, I see a few things happening:
1. Obviously your CH is over the top high. At 1,000 or more, there's not much you can do but change it. But most people in the southwest do their water exchange in the winter (Dec-Feb) if possible so that the plaster isn't exposed to the brutal sunlight.
2. Normally, maintaining a lower pH is good to help counteract the elevated CH to avoid scale, but with a heater I don't recall. @JoyfulNoise can you confirm please? With a high CH, can water still have a low pH without causing erosion to the heater?
3. I'm surprised your water hasn't gotten cloudy with a relatively low CYA and FC for that area. That's probably why you are burning through chlorine fast. Even though the water is clear, at some point you may want to do an Overnight Chlorine Loss Test to ensure there is no algae - even if you can't see it.

Let's wait for Matt to reply about the heater and pH, but I suspect a good water exchange may be one of your first requirements. If you can't do it now, then preventing algae until the winter may be next. The iron in the water had to come from somewhere, I just don't recall anyone else form the area there having an iron problem. But with iron, a water exchange should help. Now we need to figure out where it came from.

 

[Texas Splash]

Here is the report:
2020 Annual Water Report

 

[JoyfulNoise]

Keep the pH in the recommended range (7.2 to 7.8). Low pH promotes corrosion of metal surfaces irrespective of CH or TA levels. Staying within the recommended range lowers the risk of water becoming corrosive towards metals.

If the CH is over 1000ppm, you need to drain and refill but only do so safely. Fiberglass pools cannot be drained completely without mechanical bracing so you will have to do an exchange drain. You can look that up on the forum.

Also, consider a whole-house water softener installation with a run out to your autofill or a soft water outdoor spigot to fill your pool with. Water in the desert Southwest is full of calcium and mineral hardness. Removing it makes pool care a lot easier.

 

[mknauss]

I have noticed that the white goods in our pool (drain covers, eyeball outlets, skimmer, skimmer basket) have become dingy looking after 6 years. I pulled off the drain covers in the spa and dumped them in a gallon of water with some vitamin tablets dissolved in it and boom! they are perfectly white. So our Colorado River water has a bit of iron in it. Takes a long time for it to finally show up, and I would suspect a normal water softener will remove the small amount we have. I will be doing an AA treatment before I exchange the next time.

 

[Donna P]

Funny it's mentioned, but I DO have a whole-house water treatment system. The original fill (in 2019) came from the water spigot outside (which is NOT treated water) but my partial refill back in April was from the water softener. Unfortunately, I think the salt ran out as it was filling (Another household device that I finally had time to research and read up on during this whole quarantine-pandemic-out-of-work- thing). In addition, I finally sealed my pavers around the pool, and they looked great, except when pool water sat on them. The water left white circular calcium rings (very visible because they're dark grey) , and the manufacturer told me my water had mineral deposits in it and there's basically nothing I can do about it (then WHAT IS THE POINT of paver sealant?!?!) Arghhhh!!!

Anywhoo,.... SInce the last AA treatment, there's been no sign of staining and the water is very clear and clean, so I'll keep on with my maintenance routine, but I'll take Matt's advice on keeping the PH up- I don't want to ruin any equipment. I have the filter serviced by a pro twice a year, so I"ll have him do another partial drain next time. For now I'll keep an eye on the weather, because it's makes sense to me that iron-rich soil landing in the water during major dust storms would deposit iron stains on the fiberglass.
But I'm no dirt-scientist so who knows.
Thank you all for your valuable insight.