Ascorbic Acid...confused about sequestrants/cheleating solutions

Sep 18, 2013
39
San Rafael, CA
I was able to determine the stains in my pool are indeed metal...the local pool store gave me a small bag of Ascorbic Acid which I put in a sock and held it against a stain. It worked well - so well that I ended up dumping 2kg of it per the instructions found on TFP. (Sourced it from Amazon) Prior to the treatment, I let FC drop to 1-2 and lowered PH to 7.5. My CYA is quite low (~20) from the winter rains - I'll rebalance pool chemistry once this treatment is complete.

There was a noticeable improvement in the staining, but at least another course will be necessary.

(We purchased the home ~2.5 yrs ago. I have extensive staining in the pool from years of neglect. I believe the source of the stain is from rusting/deteriating galvanized piping in the home (water source) as well as a failed pool heater. The CYA level was in excess of a 1000 but is now under control - I don't think this pool had its water drained for decades.

Here is the question:
My intention was to use a Jack's...but the local store doesn't carry it. Unbeknownst to me, they dropped Jack's line and now use Natures Metalfree product. I needed something quickly (already dumped in the Asorbic Acid), so I picked up a 1L bottle. Per the instructions, I need to add some each week - this stuff is expensive.
http://naturalchemistry.com/residential-products/detail/metalfree/

I know that I need a sequestrant/chleating solution, but adding some each week seems excessive.
1. Should I try to source Jack's prior to treating the stains adding another 2kG of Ascorbic Acid?
2. Will I need to add Jack's every week? Seems expensive.
3. Should I look for a better HEDP? Which Jacks would be best?
4. Will the filter ever remove the chelated metals? (If the stains come back, does that mean my filter cartridge is bad?)
 
I was able to determine the stains in my pool are indeed metal...the local pool store gave me a small bag of Ascorbic Acid which I put in a sock and held it against a stain. It worked well - so well that I ended up dumping 2kg of it per the instructions found on TFP. (Sourced it from Amazon) Prior to the treatment, I let FC drop to 1-2 and lowered PH to 7.5. My CYA is quite low (~20) from the winter rains - I'll rebalance pool chemistry once this treatment is complete.

There was a noticeable improvement in the staining, but at least another course will be necessary.

(We purchased the home ~2.5 yrs ago. I have extensive staining in the pool from years of neglect. I believe the source of the stain is from rusting/deteriating galvanized piping in the home (water source) as well as a failed pool heater. The CYA level was in excess of a 1000 but is now under control - I don't think this pool had its water drained for decades.

Here is the question:
My intention was to use a Jack's...but the local store doesn't carry it. Unbeknownst to me, they dropped Jack's line and now use Natures Metalfree product. I needed something quickly (already dumped in the Asorbic Acid), so I picked up a 1L bottle. Per the instructions, I need to add some each week - this stuff is expensive.
http://naturalchemistry.com/residential-products/detail/metalfree/

I know that I need a sequestrant/chleating solution, but adding some each week seems excessive.
1. Should I try to source Jack's prior to treating the stains adding another 2kG of Ascorbic Acid?
2. Will I need to add Jack's every week? Seems expensive.
3. Should I look for a better HEDP? Which Jacks would be best?
4. Will the filter ever remove the chelated metals? (If the stains come back, does that mean my filter cartridge is bad?)

1. If you can source Jacks, that would be great.

2. Yes, this is the problem with metals. As long as they are in your pool water, you must control them. All sequestrants will be oxidized by chlorine, there's no getting around that.

3. Jacks Magenta stuff is based on polyacrylic acid. It works better than HEDP BUT it is incompatible with Polyquat algaecides or any form of cationic (+ charged) clarifiers. Mixing those will cause a cloudy mess.

4. No, the filter can not remove chelated metals only those metals that precipitate out of solution. Unfortunately, the precipitation is more likely to happen on your pool surfaces and not in the filter or bulk pool water.
 
1. If you can source Jacks, that would be great.

2. Yes, this is the problem with metals. As long as they are in your pool water, you must control them. All sequestrants will be oxidized by chlorine, there's no getting around that.

3. Jacks Magenta stuff is based on polyacrylic acid. It works better than HEDP BUT it is incompatible with Polyquat algaecides or any form of cationic (+ charged) clarifiers. Mixing those will cause a cloudy mess.

4. No, the filter can not remove chelated metals only those metals that precipitate out of solution. Unfortunately, the precipitation is more likely to happen on your pool surfaces and not in the filter or bulk pool water.

Wow...awesome response & speed! Thanks..

Followup on Number 3:

I assumed Natures Metalfree HEDP based on other posts. Any issues with switching to Jacks Magenta? and causing a cloudy mess?

I never use algaecides. I've done battle with yellow algae each season via SLAM and proper FC - even after getting the CYA under control. I've pulled the light and cleaned it several times, scrubbed the cartridge filter bowls, tossed the old Legend cleater ...only thing I haven't checked is the drain. Would an algaecide help in this case or is polyquat a replacement for SLAM?
 
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Wow...awesome response & speed! Thanks..

Followup on Number 3:

I assumed Natures Metalfree HEDP based on other posts. Any issues with switching to Jacks Magenta? and causing a cloudy mess?

I never use algaecides. I've done battle with yellow algae each season via SLAM and proper FC - even after getting the CYA under control. I've pulled the light and cleaned it several times, scrubbed the cartridge filter bowls, tossed the old Legend cleater ...only thing I haven't checked is the drain. Would an algaecide help in this case or is polyquat a replacement for SLAM?

Jacks Magenta would be ok to switch over to once you've finished using the HEDP sequestrant up. Overlapping their use probably wouldn't cause any issues but it's best to just finish using one and then switch over to the other.

If you use Jacks Magenta stuff, you can not use any Polyquat. If you stick with the HEDP stuff, then you can use Polyquat. Polyquat is NOT a replacement for a SLAM. Chlorine is the only way to completely kill algae. Polyquat would be used as an adjunct to proper chlorination but it will be costly because it breaks down and must be constantly replenished.

Do you winterize and close your pool?

What target FC and CYA levels are you using?

Do you manually chlorinate or do you use an SWG?
 
Jacks Magenta would be ok to switch over to once you've finished using the HEDP sequestrant up. Overlapping their use probably wouldn't cause any issues but it's best to just finish using one and then switch over to the other.

If you use Jacks Magenta stuff, you can not use any Polyquat. If you stick with the HEDP stuff, then you can use Polyquat. Polyquat is NOT a replacement for a SLAM. Chlorine is the only way to completely kill algae. Polyquat would be used as an adjunct to proper chlorination but it will be costly because it breaks down and must be constantly replenished.

Do you winterize and close your pool?

What target FC and CYA levels are you using?

Do you manually chlorinate or do you use an SWG?

OK - to confirm, I haven't found a source for Jack's yet. Another 4lbs of AA showed up today. I might look for another day or so, and but use more another bottle of Natures Metal Free before the Jack's show up via mail.

Thanks for confirming the Polyquat - in the AA conversations, I've seen the TFP gurus recommend its use to control algae during AA treatments. Since I don't have any algae growth right now, looks like I don't need it. Cool...one less thing to spend money on. Pool temps are in the 50s right now. Cover has been off.

As a heads up, I have a few threads going about my pool - so I want to be respectful of the forum and not posting on the same topic in mult forums. My general pool chem discussion is here: http://www.troublefreepool.com/threads/110970-Impact-of-Winter-Rains-amp-Chem-Level-Reset-advice-needed

WRTO closing/winterizing. Since we do not have an automatic overflow drainage system, we have to use a pump. I lost count around 18 instances of pumping - but I estimate to be 18-22 instances. Each time the water level is dropped ~2.5-3" - that suggests we've had 50-60" of rain since December. Note: we're in San Rafael CA, a Mediterranean-like climate. Closing a pool is little more than adjusting pump run times and leaving the cover on.

Last season:
CYA average 50,
FC 3-4 mark. CC was always 0 until the yellow algae would start.
Chlorine source is manual, 12% from pool store.
Last year, TA was 90-100 or so. CH around 300.
Borates at 50.
Always battling PH rise.

Target CYA will be 40. Target Borates ~50
TA will be ~70 in hopes of battling rapid/high PH rise (no aeration sources).
FC, PH will follow TFP guidelines.
 
Giant Milky Mess!

So today the pool temps started to come up a bit since we've had a batch of warm weather and wokeup to a completely milky mess.
3/25 : 2kGs of AA treatment
3/26: Bottle of Nature's whatever Metal Free
4/1: 2kGs more of AA Treatment
4/2 : Added 1 bottle of Jacks Magenta

Been adding Chlorine to keep the levels around 1-3.
Noticed pool getting clouding on 4/3. Been running filter 24-7 since 2nd AA treatment

Today...Milky Mess.

Latest Stats:

PH 7.2
TC 0
CC 0
TA ~100
CH 370
Borate 40
CYA < 20

Added 2lbs of CYA via sock in skimmer
Added 2 bottles of 12% Cl 20 hours apart. 1st bottle of Cl resulted in no change to FC or CC (where in tarnation did it go?). Just added 2nd bottle.

Hopefully someone will respond...
 
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Here are some additional fun facts. Pool water that was accidentally splashed up has left purple staining in the coping. Also the pool filter psi has risen to 6 PSI from 3-4. I did debris removal, but no vacuuming (and the pressure side legend has been broken for some time now)

via pyramid energy waves.
 
Are you trying to follow this process? Ascorbic Treatment to rid Pool of metal stains

It says to rebalance the water 24 hours after adding the AA. And to keep adding chlorine until it holds. Ascorbic acid consumes chlorine and you have to keep adding until it holds.

Why did you perform a second treatment a week later? Did you rebalance the pool in between? Were there still stains?

I am not that familiar with AA treatments. Are you following a different treatment plan?
 
Are you trying to follow this process? Ascorbic Treatment to rid Pool of metal stains

It says to rebalance the water 24 hours after adding the AA. And to keep adding chlorine until it holds. Ascorbic acid consumes chlorine and you have to keep adding until it holds.

Why did you perform a second treatment a week later? Did you rebalance the pool in between? Were there still stains?

I am not that familiar with AA treatments. Are you following a different treatment plan?

The total consumption of chlorine is new as was the cloudiness of the water. AA was repeated due to high levels of staining. A pool pro who saw the pool and had done many AA cycles before, suggested I plan for two cycles and slowly return the water balance over two weeks to allow the chleating agents to work in the colder water. He was right about the staining - one course was not sufficient. A second course has helped significantly. I've maintained the Cl levels as low as possible, coincident with my low CYA, and kept the PH low to keep the metals in suspension until the chelating agents work. This logic holds per various AA postings I've researched in this forum.

My guess is the Natures Metal Out reacted with Jacks Magenta...and the whole process was delated due to cold temps. I have nothing to base that on...just intuition of mixing various chelating agents and the reaction was stalled. I've never used Polyquat and not used any phosphates clarifing solution in 2 yrs.

Im hoping Swampwoman or one of the AA wizards responds.
Are you trying to follow this process? Ascorbic Treatment to rid Pool of metal stains

It says to rebalance the water 24 hours after adding the AA. And to keep adding chlorine until it holds. Ascorbic acid consumes chlorine and you have to keep adding until it holds.

Why did you perform a second treatment a week later? Did you rebalance the pool in between? Were there still stains?

I am not that familiar with AA treatments. Are you following a different treatment plan?


via pyramid energy waves.
 
Good morning...I will check back after my early morning meeting to read more carefully your process, but in general it is possible when using a sequestrant to have temporary cloudiness -- its possibly calcium and should filter out in a day or so.

That said, it is also possible to get milkiness if HEDP and EDTA are used simultaneously -- I will check metal free's formulation.

Regarding fast FC consumption, this is typical with AA. The AA and chlorine will do battle until the chlorine has oxidizes the AA. If you've completed the stain removal part of the process and wish to bring up the FC, you will need to continue to slowly add chlorine until it holds.

Lastly, based on my own experience, AA doesn't work as well in cold water as in warm...so leaving it a bit longer in colder water will improve the effectiveness -- which is pretty much as you have done with two treatments. So just confirming this element ;)

At this point, hopefully a day or two of constant filtering will clear the milkiness for you, but keep us posted!

Update: earlier in the thread, you said you'd used Metal Free by natural chemistry. On their MSDS sheet they cite only Citic Acid as a component...close relative to AA, but their stuff also usually has "proprietary ingredients". So I would not be overly optimistic about the product's capacity to sequester, at least in the way intended by the AA instructions.

Did you use Jack's Magenta because you have a salt water generator? Or did you mean you used Jacks Pink for iron?

If the Magenta, which I think I read is negatively charged, has combined with something in the Metal Free, them that is the source of the milkiness.

I'm afraid you will need to see if it filters out - which it should in theory either way (calcium or product reaction) - before taking any drastic measures.

I would suggest calling Jacks Magic and asking to speak with a tech for advice if clarity hasn't improved in 24 hrs or so.

Sorry I don't have better suggestions ;)

Ps I'm not entirely sure you should be adding cya to this mix just yet until you've gotten FC up and the sequestrant battle has resolved...if things are combining/reacting, I'm not sure the cya will dissolve properly.
The purple staining you mentioned might be cya-related. Take the sock out for the moment if you can -- another day at lower cya shouldn't hurt ;)
 

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Well it cleared and precipitated onto the floor of the pool. I brushed a little bit of it to confirm the solids indeed appeared to have fallen out of sol'n. Not knowing if it is also AA, I left it there. Pool cleaner is off.

I pulled the sock out and set it into a bucket...hard to say how much was consumed, but didn't look much different.

TC 0
No chlorine present
PH 7.2 or a scoche lower.
Didn't bother doing anything else.

Hopefully this white dust will get filtered out. Any ideas what this might be?

WRTO Jacks - I used magenta as thats what folks seemed to have used in other threads. I do not have a SWG...Cl is all manual via liquid. Did I use the wrong stuff?

Staining appears to be unchanged from first treatment...beginning to suspect I wasted time and money...and have just saved up / budgeted for an acid wash.

via pyramid energy waves.
 
At what point did you add the Magenta? How long has the AA been in there now? Generally, in non-swg the preferred sequestrants would be jack's pink for iron or metal magic by Haviland. In other words, HEDP.

Best thing here would be to bring your FC up carefully. Eg. Dose, test in a half hour to see if holding, dose a bit more, but dont overshoot. You don't want to run it high, just to bring the level up slowly -- but do not leave at 0 FC.

Tomorrow why not just Vacuum out the recipitate if its still there then put the sock back in.

Do you have any idea if your stains were iron, or were copper? Are you on a well?
 
Thx for all the help!

Magenta went in the pool on the 2nd.

I think its mostly iron. I have copper lines (pool from the 60s), but badly corroded galv piping in the home and old main supply lines. Also there was ancient pool heater that was dead...last time I tested for copper, it was false.

The purple staining showed up after Jacks went in...there was some dark staining on the coping from splashes after Nature's Ripoff went in (only kidding about the name, not the staining).

Well I guess I screwed up on the Jacks.
The AA has been in there 7-10 days at this point.

We're at the end of the water line - neighbor had a particulate filter that was pretty rusty. Lines seem fine now - all house lines have been changed to copper.

I just brushed a bunch of the precipitate towards the drain and will vacuum it up tomorrow. (Takes forever...) Also explains why the filter is showing higher PSI. So you think the precipitate is calcium?

I'll start to bring FC backup slowly...just out of curiosity, why the need to go slow? The pool is still a bit cold to use at this point, so an overshoot wont matter much.

via pyramid energy waves.
 
High PH and/or high chlorine levels can cause unsequestered metals to stain again. So, the idea is to raise it slowly and if you see staining reappearing then stop and add more sequestrant to prevent additional staining.
 
+1 ^ re slowly...its just so that you don't actually end up with a high FC
When I've done it, that can look like dosing several times until its holding for a day, then bumping it up the next day. Don't ride low for toooo long.

Re: Using Magenta...Jack's line has gotten a little robust of late so its a completely understandable mistake and for that matter, not even really a mistake per se...on the plus side, its good that they have options formulated for different conditions...on the down side, its confusing as heck.

My understanding is that magenta was formulated in particular for SWG and new plaster start ups to help control the plaster dust as well and keep your cell clean. So I'm guessing it "picks up" any stray calcium too, or calcium that binds with metals. Perhaps you'll find since you're not on well that this treatment, despite the mess, has now actually caused much of the free metal to bind and ergo, be removed -- which will ultimately have made it worth doing ;)

A couple of years back I'd switched to Metal Magic, which in my pool, also did a good job on any stains from iron if I did the sponge test (holding some on a stain and then dosing according to his long it took to remove.) I did that not because AA doesn't work, but because I hated trying to get back to normal after ;) This way, I was sequestering the iron anyway, plus removing mild iron stains.

I think you've had quite enough experimentation for a spell, so I'm not suggesting you do this, btw. But I wanted you to know of an alternate if you later find the stains come back darker or need to sequester. Metal Magic warns you in the instructions that it can cloud the water for 24-72 hours while your filter catches up clearing the particulate. In mine, it didn't cloud at all, but the backwash was milky.

AA is usually the most sure fire treatment for stains, but its more effective on iron than copper...my understanding is that sometimes in older stains, especially copper, there are different layers to lift and sometimes scale mixed in. In this area, Jacks has a stain ID kit that helps determine what stain formulation of theirs to use. On one hand, the increased precision can be helpful for a most effective treatment. On the other, its quite a bit more expensive in some ways to do the "all Jack's way" of stain treatment where regular bulk AA does much of the heavy lifting anyway.

If you have historic "spot" stains left over that didn't fully react/clear, there is a tool you can purchase for spot treatments either with acid or (as I've done) with Metal Magic sequestrant. I'm giving you the link in the event you want to try some extra spot treatment of areas ---AFTER you've got the balance back in order ;) You don't need to mess with the chemistry to do this, and can pick away at a trouble area ad hoc.

Ad hoc meaning while lounging around in a swim suit with beverage of choice ;)

Amazon.com : Purity Pool OS Out Spot Stain Remover : Swimming Pool Stain Removers : Patio, Lawn Garden
 
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