Borates and Iron Stains

[lews]

I'd appreciate some help. I currently have some iron staining on my plaster SWG, 24,000 gallon 8-year old pool (cartridge filter). The iron comes from topping off with well water. I do not have borates in my pool now, and would like to establish them at 30-50 ppm. I have 3 pounds of ascorbic acid and two bottles of purple stuff and I was preparing to lift the stains, but would like some advice on how to combine the borates. Borax raises pH but there's also boric acid. Is it possible to use the vitamin C to lift stains, put in the purple stuff and then bring the pH back up to 7.2 using borax? Or a combination of borax and boric acid or a combination of borax and muriatic acid or washing soda?

If so, I'd like some estimates. I'm not sure how far down the vitamin C treatment pushes the pH, and I don't know how much borax, per pound, raises the pH. Assuming that I don't have enough pH room to put in all the borax I need (after vitamin c), perhaps using boric acid for some of it might work. Or, I could deal with the borax treatment before the stain lifting, or partially do so. For example, I could use muriatic acid and borax to get borates to 30 ppm and then use additional borax after the vitamin C treatment… A lot of variables, so any thoughts would be welcome.


FC-3
PH 7.8
TA110
CH 280
CYA - 60-80

Thanks,

Lewis

 

[JoyfulNoise]

… A lot of variables, so any thoughts would be welcome.

Precisely. So simplify things by forgetting about borates for the moment and follow the AA treatment process. Getting rid of the stains and keeping them from coming back is more important than adding borates at the moment. We would never advise anyone to do as you suggest which is attempting to adjust multiple parameters all at once.

Your bigger concern should be how to limit your use of the metal contaminated fill water. Unless you find a way to actually lower your pool's metal levels, the stains are going to come back.

 

[lews]

Precisely. So simplify things by forgetting about borates for the moment and follow the AA treatment process. Getting rid of the stains and keeping them from coming back is more important than adding borates at the moment. We would never advise anyone to do as you suggest which is attempting to adjust multiple parameters all at once.

Your bigger concern should be how to limit your use of the metal contaminated fill water. Unless you find a way to actually lower your pool's metal levels, the stains are going to come back.

I'm open to idea on how to limit use of contaminated fill water. It's not practical to truck it in. I use a Terminox whole house system for iron and manganese treatment, and that helps. I also use a garden hose Shurflow filter (for RVs) as a secondary filter. I thought a key reason to add Borates is a more stable PH, which should help with the iron staining.

 

[JoyfulNoise]

I'm open to idea on how to limit use of contaminated fill water. It's not practical to truck it in. I use a Terminox whole house system for iron and manganese treatment, and that helps. I also use a garden hose Shurflow filter (for RVs) as a secondary filter. I thought a key reason to add Borates is a more stable PH, which should help with the iron staining.

Using a pool cover helps to limit evaporation. Most home-based filtration systems only filter water on the inside plumbing loop of a home. External spigots are typically plumbed on a separate loop to the main water source. Do you have a specially plumbed spigot that uses treated water?

Yes, borates can help with pH rise but we never advise adjusting or adding those in the context of another process (i.e., AA treatment). You should perform the AA treatment, as described in the Pool School stickie, and not add any other chemicals to it.

If you want to decrease your pH rise, your bigger problem is a TA of 110ppm not the fact that you don't have borates. If you lower your TA below 80ppm (you could go as low as 50ppm), then your pH rise will be a lot slower. Carbon dioxide outgassing from aeration is the biggest single driver of pH rise in pool water. Lower your TA and you may find you don't need borates at all.

 

[lews]

Yes, the spigot is treated water. At least, the one I use.

I am contacting the local pool supply to check on the price of the drain and fill. If I drain and fill the water, can you provide some recommendations on how to get the iron in solution during the process of draining. I would assume that I would use the AA treatment and then drain the pool while the stains are lifted but I'm a little concerned about how long it will take to drain the pool. I do not have a plumbing system that allows a direct drain out, so I'll have to open the drain on the cartridge filter holder. I did a quick search for drain and fill on the forum and didn't see any applicable posts. I live in the middle of North Carolina and the pool is on the side of the rockyish hill, so I'm assuming that water pressure concerns should not be an issue. The pool store did not think so. Also, does it make any sense to perform any sort of maintenance to the pool surface while it's drained? If the stains return in the process, maybe an acid wash - I'm not familiar with that.

 

[JoyfulNoise]

A couple of thoughts here.

First, you can drain a pool by simply renting a high speed submersible pump from a local hardware store (Lowes or HomeDepot). Get one rated for 3,000 to 5,000 gallons per hour and you'll be able to drain the pool in a few hours.

If you follow the AA treatment including adding sequestrant, then you will redissolve all the metal and keep it in solution. Then you drain that water.

If you purchase fill water, you have to ensure that you are getting metal free water. Some water suppliers will simply drive their trucks to the nearest fire hydrant and fill up. If that water is not metal free, then you'll be back in the same situation. If your local municipal water (from hydrants) is treated and metal free, there is an off-chance the local fire department can help you out. There are some fire departments that will fill your pool for you from a local hydrant if you make a "donation" to their fire-fighter fund. Call you local fire district and ask them if they do that. Better to give firemen your money than some random trucking company.

Finally, acid washing is almost never a good idea. Acid washing removes the calcium carbonate cured layer from your pool surface and does so in a way that makes the plaster surface more rough and porous. That's worse for metal staining, not better.

 

[lews]

Thanks Matt,

I spoke to the pool place and cost $1500 for the fill water, and as you say, there's no assurance that it will be without problems. For all I know, the iron in my water came from the original fill water anyway, as I've been extremely careful with topping it off. The pool store also said that a sequestrant like jacks or metal magic should deal with the problem. But he also said that it would bind with the metal and I could filter it out after a day or so, and I know that's not true. Also, I gather from your comments that the only way to deal with the problem is to get water without metal in it. Argh...

To decide whether it's better to try to deal with the iron with Jack's or attempt to find clean water and pay a lot of money, I would think that the concentration of the iron in the water would be a consideration. Should I see if I can find the concentration of iron in the water? The pool store said that they could test that. I still would need to know what concentration would be workable for a sequestrant and what would justify a drain and fill. What do you think?

BTW, I just tried a local fire station - no go.


Edit: let me restate. From looking at all the comments on the forum, the consensus seems to be that trying to manage iron is a losing game. If that's true, then there's only one solution - refill. Am I correct that this is the consensus, or is it a manageable proposition to sequester with close monitoring, assuming the iron concentration isn't too great?

 

[JoyfulNoise]

PM'd our resident "iron in pool water" expert (maybe we should rename her, The Iron Lady?)...she'll be along shortly.....

 

[Swampwoman]

Hi guys...so sorry didnt see this til now...my posting time has been dramatically reduced lately with some health and family shenanigans but its all good.

First off, Lews, and I promise more on this tomorrow (have to get up at 5 am for a meeting) can you please go ahead and get readings on your pool water and your fill water post hose filter and your actual raw well.

That will help me help you assess what most viable and cost-effective.

If my hunches are right, I'm betting the trucked water is not the best financial plan since you're already capable of reducing the load, you haven't been sequestering, but with swg if you use Jacks Magic Purple specifically I suspect that will put an end to the staining in th swg environment (other types dont work n high tds) and lastly, if its all iron, the AA treatment should clean up your plaster.

So you can buy several years worth of Jacks and a lot f AA before your approaching 1500

With borates, which I also use and dose, I'd rather see you treat after you've resolved on staining. Ths is most compatible, because after AA and with sequestrant treatment, it will be helpful to actively lower your ph with MA, whch will help you drive your TA down. You want a lower TA before you add borates because its harder to move the dial once you treat.

You could see if pool store will read all three, or if you have service for your house system, they coud read all three, or you could pick up a cheap Lamotte insta test for iron and read all 3 sources. Then report back.

Cheers, Swampy, Iron Lady, or at this rate, ironside

 

[Swampwoman]

Hi again. Here are some more questions, plus an observation that my help going forward

First off, not familiar with Terminox except that it backwashes. What size is it and what ppm removal is it rated for? How many gallons until it requires backwashing/regeneration?

Here's why I ask -- it will help determine how the iron is getting in.

My well is 2 ppm iron and I have a dual whole house softener. I should have added the Iron Curtain to the system when first installed (a greensand system) but the water guy was sure the softener would nail it (another debatable statement.)

With the iron curtain, some households require up to four tanks depending on ppm, water useage, etc.

With my softener, hen I first started using it on the pool
The iron load wasn't dropping very fast. I kept testing the output, which was certainly lower, but wat took me the better part of a season to figure out is that I was exceeding my capacity on top up days and ergo actually putting raw well water in the pool when the unit would regenerate.

In my case (water table issues - my pool is on side of hill where a storm water catch basin used to be just outside a flood plain on a river ) it was worth it to upgrade to a dual softer system so that one would regenerate without interruption of treated water. With the softener's, it gets all but from .2-.5 of the iron, whch I still filter at hose as you d, and still maintain with Acs Ourple but at a much lower rate of useage.

Your terminox might tap out now and then on fill and ergo let iron in when you're not expecting it.

So by testing at hose, well, and pool...you can get a sense of what would be manageable. If before sequestrant your pool is higher than everything else and it would take a year or two of top ups to dilute it, you ay find at least a partial drain worthwhile.

But if you find the terminox has adequate capacity for most tops ups, gets most of the iron out, further reduced by RV filter or enhanced filter (you could blurb a big 10" housing with a 1 micron filter) and your actual level in the pool responds well enough to sequestrant, you could just slowly reduce over time. My iron is finally down to .1 ppm this season

Of course, now that I have completely manageable iron, I've bought a new lner and have to dump the whole thing and start over with trucked water!

 

[lews]

Hi again. Here are some more questions, plus an observation that my help going forward

First off, not familiar with Terminox except that it backwashes. What size is it and what ppm removal is it rated for? How many gallons until it requires backwashing/regeneration?

Here's why I ask -- it will help determine how the iron is getting in.

My well is 2 ppm iron and I have a dual whole house softener. I should have added the Iron Curtain to the system when first installed (a greensand system) but the water guy was sure the softener would nail it (another debatable statement.)

With the iron curtain, some households require up to four tanks depending on ppm, water useage, etc.

With my softener, hen I first started using it on the pool
The iron load wasn't dropping very fast. I kept testing the output, which was certainly lower, but wat took me the better part of a season to figure out is that I was exceeding my capacity on top up days and ergo actually putting raw well water in the pool when the unit would regenerate.

In my case (water table issues - my pool is on side of hill where a storm water catch basin used to be just outside a flood plain on a river ) it was worth it to upgrade to a dual softer system so that one would regenerate without interruption of treated water. With the softener's, it gets all but from .2-.5 of the iron, whch I still filter at hose as you d, and still maintain with Acs Ourple but at a much lower rate of useage.

Your terminox might tap out now and then on fill and ergo let iron in when you're not expecting it.

So by testing at hose, well, and pool...you can get a sense of what would be manageable. If before sequestrant your pool is higher than everything else and it would take a year or two of top ups to dilute it, you ay find at least a partial drain worthwhile.

But if you find the terminox has adequate capacity for most tops ups, gets most of the iron out, further reduced by RV filter or enhanced filter (you could blurb a big 10" housing with a 1 micron filter) and your actual level in the pool responds well enough to sequestrant, you could just slowly reduce over time. My iron is finally down to .1 ppm this season

Of course, now that I have completely manageable iron, I've bought a new lner and have to dump the whole thing and start over with trucked water!

Sorry for the delay, we had a family emergency to deal with. Matt, thanks so much to PM SW. SW, such good advice. It sounds like it would be important to have a regular measure on iron, so I'm going to purchase the testing you mentioned. I don't know the specs on Terminox (Water Filters-Iron Filters-Water Softeners), but it seems more important to test it regularly (filtered and unfiltered) to make sure it's working and what I'm dealing with. I know there's a manganese issue as well as iron. I've seen that more recently in my toilet and through a recent test with the county. I'm see more staining in my toilet - which is why I had it tested. In discussing it with budgetwater people, they say my ph is probably fluctuating, which makes the filter system less effective. Anyway, let me get a test kit and post the results. Thanks so much.

Lewis

Edit: Test kit will be here Saturday.

 

[Swampwoman]

Sorry about your emergency and hope all is well.

I think if you're getting mag in toilet its a sign that the media on the terminox is fouled, needs deep backwashing, or possibly the unit is not matched to your flow and load etc...and i suspect ergo its been passing iron to the pool incrementally, where the load has built up over time.

I read a few things on the site and didnt find the info terribly transparent but they seem interested in protecting their approaches from copycats so don't have specs or ratings, which is mildly concerning from a DIY/diagnostic standpoint. Then again, its a complex topic, and perhaps they want to avoid unintended consequences if I were being cynical, I might say that this is also a way to keep you on-product and reliant on their intel Either way, you can test your own ph on raw well water and report to them for dx.

My best guess is the terminox is a pyrolox variant -- these media filter type require high ph to operate correctly. They also won't necessarily work right if you have iron bacteria as well. Not that you're in the market, but I think my plumber/water guy kinda prefers air injection systems or hydrogen peroxide, fwiw, and that he wasn't even in love with a maganese greensand system that cost twice what the biggest terminox does. Not sure why -- I think fouled resins and ph requirements were concerns.

It was a few years ago that we'd talked about all that. It might have just been that in my water treatment area footprint i didnt have room for additional tanks, which i don't -- i had to go one route or the other -- softener or mineral treatment tank as i recall. Its the main reason I've not bothered to add an iron-specific tank to the setup. I'll see if I can get more info from him.

So I'm not any kind of expert on the different kinds of iron/mag filters myself as I don't have one (though i did have a client about a decade ago who was an indie trainer/expert for big water companies, so i have a bit of familiarity with the technologies from then.)

I think in your shoes I'd use the company's support to get the filter dialed in and corrected as needed before moving on to stain removal from the pool because longterm you'll be in a better position to manage.

In general, what I'm finding whether its pool water, spa, whole house etc. is that DIY testing for load and consciousness of capacity helps in terms of management.

For example, your RV filter will be rated for x-gallons at y-flow. Over time, it will let more iron through, especially at higher loads. So changing out the filter after 5,000-8,000 gallons on the small hose type is a good idea. I've now switched to fitting a 10" Pentek blue housing filter and using a 4.5" 1 micron disposable filter to my fill hose so that I can just switch out the filter cheaply. If you do this, you need fitting to convert the not connection, but its a cheap, easy thing

Calculating the gallonage required for a one or two inch top up in your pool is also a good idea, because it will tell you the treatment capacity required in a single instance. That's how I determined I needed dual treatment tanks -- I dont cover so I have a lot of evaporation at times due to my idiot preference for 88 degrees so i was exceeding the tank's capacity

At a any rate, whenever you post back I'll take a look and at least give you info to compare to.

And just in case you're thinking its time for a switch or the current comany tries to upgrade you and you want to look at different options, here's one I've thought about replacing my dual tank with if I ever decide to tinker further with my system (which I might, with new liner and $1,000 in new water coming Air Injection Iron, Sulfur, and manganese Removal Oxidizing Water Filter For Whole House, AI25 2510SXT - - Amazon.com
-Have not vetted this with my friend as I have too many other projects going on

 

[Vickery]

My well water is hard enough to crack a tooth with iron, sulfur and calcium. Raw ph is 6.8, TA is 220. My new fill this summer looked like a red clay pond after a hard rain. Jack's wasn't available in a timely manner - to prevent staining my new liner - so I used a different sequestrant -Sea Klear- dosed my sand filter with a small amount of fiber to increase filtration and ran the pump 24/7, back washing and adding fiber each time. Four days later and the water was clean. The red line around the pool has been fading as I brush it, some iron continues to precipitate out but the filter seems to catch it. Now I have TFP water - sparkles like a diamond!

 

[basod]

Vickery I think I'd caution people to believe the results of a bit of fiber filtering ALL the iron from the pool. There is still likely dissolved iron undetecable by most tests due to the chlorine in pool water. 3 types of iron exist in well water ferrous iron is dissolved iron, ferric iron is suspended(this is can be filtered with fiber), and iron fixing bacteria that are killed by chlorine and put iron into solution. The main trick in all iron pretreatment is to take ferrous iron to ferric iron through oxidation. This can be done with air or better with bleach. I have test setup similar to whole home filtration for both filling my pool and side stream polishing it worked successfully in basic filtration mode but I've expanded the setup for air/bleach induction with time contact to prevent iron from entering the pool to begin with.