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Thread: Metals and sequestrants * Warning - long post*

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    Metals and sequestrants * Warning - long post*

    First of all, mods, please move this if it would be better suited elsewhere.

    Second, I just had half of this typed and the power went out, so now I get to start over.

    from-blue-to-green-in-96oz-t19931.html#p164075

    Okay, now the topic above got me thinking...and wondering...and making a long drawn out post to ask some questions.

    We are on well water out here, and not surprisingly, we have metals in our water. Specifically, ferrous iron. Depending on the time of year, it can be low (1-1.5ppm) to extreme (5ppm, verified by multiple locations) and a major pain in the ***. The last time we had a pool was around 3 years ago, and between the metals and complete lack of time to take care of it, we took it down. It was an Intex metal frame, so it was just easier to take down than have it become a giant mosquito nest.

    Anyways, I followed the advice at PoolForum (fill pool, add sequestrant and Poly60, wait about a week, then gradually raise CL). Within 5 minutes of adding even a small amount of bleach, BAM! Dark, dark brown pool tea. I tried the whole sequence over and over, adding more and more sequestrant each time, no change. After 3 or 4 times of doing that, I was ready to drain the thing and set it on fire. We tried different products, HTH Metal Control, Sequa-Sol, and Metal Free. I don't know if the HTH is less concentrated (after all, it is cheaper than all the others out there!) but that was the only one we could buy regularly. The Metal Free was a joke, at something like $35/bottle, and I couldn't get anything else except for online.

    Now for some questions. The HTH says on the bottle not to add more than 1 quart/10,000 gallons for 1 ppm metals. Is that because using more could precipitate calcium out of the water? That Intex was only a little more than 5,000 gallons IIRC, and the last couple drain and refills I was using 6-7 bottles just for a startup dose. Seems a little excessive to me, but I'm not a chemist nor a pool expert. Or is it maybe that the HTH is just too weak for what I need it to do?

    Our well water consistently has (and did even back then) a pH of 7.0-7.2, and I would always start out with 6-8 oz. of bleach, which according the the pool calculator would keep my CL well below 1, so I've always been stumped about getting brown water that quickly.

    The only thing that worked was something bk406 talked about in topic above, except I did it on purpose. I shocked the pool to at least 20ppm, but in my situation the filter was WAY overmatched. Since the filter couldn't handle it, I did something that is generally not recommended here, but in that case it was necessary - I flocced the living **** out of that pool. I let it circulate the whole day, then shut the pump off that evening and let it settle. The next day, CLEAR water! Except the inch thick mass of clumped iron on the bottom. I vac'd to waste (if you need to know how to do that on an Intex, ask me, it's really easy), lost probably 6" of water in the process, but had beautiful, sparkly water!

    I refilled the pool with softened water, and everything was great the rest of the season. My water softener is at least 20 years old, and is a Culligan Mark 45. After talking with Culligan back then, I was able to determine my softener had the capacity to produce around 1,500 gallons per recharge with my CH and average 3ppm iron. That's at 8 lbs. per recharge.

    So, more questions. When I get my AGP set up, would it be better to go the 'bk406 method', the floc and vac, or dump a whole bunch of bottles of HTH in there? Or maybe even suggest a brand that would work better? If I have to, I'll try to get 55 gallon drums of HTH! Has anyone here even dealt with iron content as high as 5ppm? Maybe with a content that high, a sequestrant won't work? Given recharge times for the softener, it would take days to fill up completely with softened water!

    Wow, didn't expect this post to be this long. I'm just trying to be as prepared as possible when we fill this pool up soon, and dealing with metals in the water can be confusing to a lot of people, myself included! I understand why you get discoloration and staining, and how to generally take care of it, but I just haven't seen a situation like this on here or PF before!

    Okay, end book. Umm, I mean post.
    John

    24' round Vogue AGP 12,000 gal. Flotec AT251001-01 1HP pump, Hayward S310T2 sand filter, Aquarite SWG T-15
    TF-100 (found at TF Test Kits) with Speedstir and Samplesizer

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    Re: Metals and sequestrants * Warning - long post*

    I just wanted to say hello and good luck. Others will be along to help. I have iron, constantly deposited in my pool from my sand, silt, and dust but not nearly to the extent you have. I used the HTH all winter after doing an AA treatment for iron stains in the fall. So far, after using several different products, I can't vouch for it's strength or whether it is best for iron as sequestrate but it did loosen up a lot of scale on my pool over the winter. That's what I like best about it in addition to the price. I kept the pH at 7.2 all winter. I had about 1-1.5 iron when tested last summer.

    I'm sure someone will be along soon to get started on doing the best for your situation. Have you thought about getting the first fill water trucked in and then using the softened water for topping off due to backwashing, splash-out, evaporation? That might be one solution for your start up and probably cheaper than having to use so much sequestrate.

    The Walmart HTH, is HDEP. It does state on bottle, if I am remembering right, that it helps with scale. People claim that the AA treatment doesn't do anything for scale. If it didn't then it was the HTH metal control, used all winter, that loosened enough that it took my new Pentair Quad 80 two weeks to clear it out, after running submersible pumps, discharging into 1 micron Slime Bag, for a couple of months before that, collecting a lot of the calcium. In addition the Aquabot, using fine filtering bags, collected loads of calcium requiring several change out of bags a day.

    About a week ago I added two bottles of the HTH. My big filter is needing a backwash every week from all the clay/chalk powder that blows into the pool. I don't have any iron staining and plan on using the maintenance does (or a little more) here on out.

    Best wishes, gg=alice
    1981, 25K, IG, Blue Plaster 1996, somewhat oval, widens a bit at shallow end, 1.5" pipes, 2" at Pad, 1 separate main drain, 1 skimmer, 4 returns + dedicated cleaner return, 10 ft deep end with very fast decline from shallow, Pentair Quad 80 DE, Pentair Intelliflo VF, 3/4 HP Booster Pump (equipment pad about 8 ft below top of pool), Challanger 3/4 Trash/Emergency Pump 120v, Polaris 280 (pressure), iRobot Verro cleaner (robotic), Aquabot Turbo (robotic), Jacuzzi Tracker 4X (vacuum) Pool Blaster (Buster), Two (2) PoolSkims, Solar Breeze (solar powered top skimmer) (beta to ver. 2, release date 2010), ColorSplash LED replacement bulb. Aries 550 gal separate spa, 2002 (our 3rd and BEST spa) , BBB-Bromine

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    NWMNMom's Avatar
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    Re: Metals and sequestrants * Warning - long post*

    We have well water with a lot of iron in it as well and had chocolate brown water one year when we forgot the sequesterant before addiing water in 2006. We have used Metal Myte from Menards/Lowes and find that it works well, however, here's what we do while filling:

    We add an "inline" filter to the fill hose (the whole house cartidge filter type from home stores) with the white "Rust/Iron/Sediment" filters that go inside. Our well aslo has a double filtration system with the "Rust/Iron/Sediment" filter and then a charcoal filter after that. These filter systems can be purchased at any home store and I even think Walmart has some units. If you check the automotive section, you can even pick up a compact unit that can be installed inline on your garden hose for RVs that have similar filters but I think the home stores/hardware stores have the cheapest unit and filter cartidges. Although this does not remove all of the iron, it really removes a LOT - also we run the pump and filter 24/7 with a bit of DE thrown in each time when we first get the pool filled and backwash (add more DE after the backwash or it goes out too) - unbelievable how much iron ends up in that filter. Even with this, the sequesterant is always a requirement.
    18x33x52 Buttressfree Seaspray (Wilbar) AGP - 1.5hp Pentair Maxim w/22" Pentair Meteor Sand Filter, Aqua Rite SWG System, Biltmore Walk In Steps - 2/4x20 Solar Panel Setup - Doheny Jet Drive (RIP -Pool Rover Jr) - finally hard plumbed the whole darned thing -
    Beats Driving to the Lake!

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    Re: Metals and sequestrants * Warning - long post*

    Hey Alice, thanks for the kind words. I didn't think anyone else here was keeping the odd hours I am.

    NWMNMom, I didn't think any filter could remove iron in it's ferrous state. I thought they would only work once the iron was out of solution. We have a 1 micron filter inline to the house, and we still have the iron staining problems inside. I've always wondered if the stuff I had bought at Walmart was old and ineffective. After working there in my younger days, I found out a lot of their products can sit in a warehouse somewhere for months and months before being put in a store. Things like tools, lawn and garden products, etc. On a different note, their CYA apparently has changed from granular to more powder like. The last time I used it, it dissolved FAST.

    I'm really thinking my best option will be to fill with hard water, then floc and vac to waste and refill with softened water. I hate to do it that way, but it did work last time. I just hope I don't get major staining in the process.

    I've actually played around with the idea of making my own (larger) water softener. I can buy the resin beads from Culligan, and I have an extra brine tank. I could use another sand filter, but fill it with the beads instead. Then fill the pool, and filter the pool water through it, recharging as necessary, until all the dissolved iron has been filtered out. I could just use Poly60 in the pool, and deal with any algae I get after the iron has been taken care of. I'm still figuring out in my head, but it could be a solution.

    I'd love to get as many opinions about my situation as possible, so keep the ideas coming!
    John

    24' round Vogue AGP 12,000 gal. Flotec AT251001-01 1HP pump, Hayward S310T2 sand filter, Aquarite SWG T-15
    TF-100 (found at TF Test Kits) with Speedstir and Samplesizer

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    Re: Questions about sequestrant and BBB.

    Not trying to hijack this thread, but I have a question maybe you can answer, Jason.
    Please keep everything in one place. Thanks JasonLion

    I posted this last night, don't know if you've seen it, but how much sequestrant is too much? Is there any way to know before you get to that point?

    metals-and-sequestrants-warning-long-post-t21040.html
    John

    24' round Vogue AGP 12,000 gal. Flotec AT251001-01 1HP pump, Hayward S310T2 sand filter, Aquarite SWG T-15
    TF-100 (found at TF Test Kits) with Speedstir and Samplesizer

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    Re: Metals and sequestrants * Warning - long post*



    Anyone else have any insights? Inquiring minds want to know!
    John

    24' round Vogue AGP 12,000 gal. Flotec AT251001-01 1HP pump, Hayward S310T2 sand filter, Aquarite SWG T-15
    TF-100 (found at TF Test Kits) with Speedstir and Samplesizer

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    Re: Metals and sequestrants * Warning - long post*

    If you've got any chlorine in the water, then it will oxidize ferrous ion to ferric ion rather quickly. So you can just figure that if there's any iron dissolved in chlorinated water, it's in the ferric state. It's not so much the high shock levels of chlorine that have much to do with the formation of iron solids, but rather the high pH that results from adding that chlorine. If you raised the pH through other means, say from lye or from Borax, you should get the same result in terms of formation of iron oxide-hydroxide and possibly iron carbonate (siderite).

    The problem is that you can't readily control where the formation of such iron solids occurs. If it's in the bulk pool water, then that's fine and can be flocc'd to settle to the bottom. However, if it's on a pool surface, then it can result in a stain. Now the stain is so fresh that it might get removed just by lowering the pH back down, but that's being pretty brave because if it doesn't work then you've got metal stains to deal with.
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
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    JasonLion's Avatar
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    Re: Questions about sequestrant and BBB.

    Quote Originally Posted by cheddar85
    how much sequestrant is too much? Is there any way to know before you get to that point?
    It takes quite a bit of sequestrant to cause problems in most cases. Five times the standard dose is usually alright, ten times is starting to get into dangerous territory. Actual numbers depend on which sequestrant you are using and what some of your other chemical levels are.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Re: Metals and sequestrants * Warning - long post*

    Chem geek - The last time I tried this method was with a metal frame Intex, and luckily I got no staining at all. The whole process from shocking, to floccing, and vacuuming out took less than 30 hours. So, at least if I go that route, any stains will be relatively fresh.

    JasonLion - Thanks for answering that. Been wondering about it for a while, and have never been able to find an answer.

    BTW, I was at Walmart today, and looked at the HTH Metal Control again. I had an old bottle laying around that said to use 1qt/10,000 gal, for 1ppm metals, the new bottle there just says use 1qt/10,000 gal. So that means if I used 7 qts. before in a ~5000 gal. pool, I used ~14 times the standard dose! BUT, at the time, I think iron content was around 3ppm, so that would put it around 4.5 times the std. dose. Wow! Guess maybe I didn't use enough last time!

    Since I have a pool almost 3 times the size now, that's gonna be one expensive startup dose! Maybe the floc and vac would be better...
    John

    24' round Vogue AGP 12,000 gal. Flotec AT251001-01 1HP pump, Hayward S310T2 sand filter, Aquarite SWG T-15
    TF-100 (found at TF Test Kits) with Speedstir and Samplesizer

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