Using HydroPureTech cartridges to deal with Iron

[BJohnston]

Good to know.

Can you explain to me a little more about using cal hypo to remove my iron? I'm still pretty new to this forum and learning how to do many things.

My calcium measured around 290 the last time I measured it. Will cal hypo make that go up? Keep in mind I have a IG vinyl pool.

How long will I need to used it before going back to 8.25% bleach as my main chlorine source?

My CYA is <20 so should I adding some during this time? (I thought maybe using Tri Chlor INSTEAD of cal hypo would be acceptable because my CYA is so low)

Still not completely clear on the method to follow. I have looked at some of the other methods suggesting to keep chlorine low, obviously so the ascorbic can work correctly, and to use a sequestering agent after stains are removed. Also using Polyquat 60 during this time to keep algae down. Can you please provide a step by step for the method to follow?

[PoolDoc]

If you use it the way I want you to do, you end up depositing calcium carbonate dust (like pool plaster dust) on the filter. In addition, you are chlorinating in an alkaline (high pH ) solution, via the cal hypo.

+ Chlorine + high pH tends to convert the iron from a soluble form, to an insoluble form.
+ The calcium dust gives it an attractive place to 'land'.
+ When you backwash, you can remove the stained calcium dust, getting both the dust AND the iron out of your pool.

Using the cal hypo this way, you MUST let your pH, TA, and CH 'float'. The result will be water that is slightly over-saturated in calcium -- but that's good in this situation. Your individual CH level may go up slightly, OR it may come down a bit.

You'll need to continue doing this till all the iron is out of the pool.

By the way, this should not be much more expensive than using bleach. 1 gallon of bleach is roughly equivalent to 1 pound of cal hypo, in chlorine content.

You seem to be missing something regarding the effect of the sequestering agents: their effect is TEMPORARY. Until you remove the iron from your pool, you STILL have a problem. A sequestering agent simply hides the problem for awhile.

The COMPLETE process for dealing with stains is this:

1. De-chlorinate so a metal dissolving agent can be used (ascorbic acid, citric acid (Not recommended), sodium hydrosulfite, etc)
2. Add polyquat 60 so the pool doesn't turn green during treatment.
3. Add the dissolving agent (ascorbic acid, etc.)
4. Immediately add HEDP to KEEP the dissolved metals in the water.
5. Re-chlorinate gradually.
6. REMOVE the metals from the water via CuLator (ion exchange) or enhanced filtration (cal hypo, alum coating, etc.)

Another option is to DRAIN the pool after step #3, and refill with metal free water.

[BJohnston]

Ben,

Thanks for clearing that up and all of your helpful information, it is much appreciated. I do indeed understand that sequestering is a temporary effect and that staining can return, which is why I have so many more questions of how to successfully "remove" the iron from my water. I Just started the process yesterday.

My Chlorine level is .5 or less.
I added Polyquat 60 with my pump running on filter.
Waited 20 mins, then shut off pump to apply stain remover to fiberglass steps.
I used Natural Chem's Stain Free to remove stains from fiberglass steps, since I had already purchased it a few days ago unfortunately.
I also used SeaKlear Metal Klear, as a sequestering agent, again I had already purchased it unfortunately, it was available at my local pool store.

Results Yesterday:
The steps immediately began to turn back white. After about 30 mins they are all white except for a few vertical surfaces.
The pool looks clear and better than ever. I resumed pump/filtering. Maintaining low chlorine level. I also took the time to top off my pool. Used my hose connection outside that utilizes water that passes thru my water softener and whole house carbon filter. Filled thru skimmer basket with pump running.

This morning:
The entire pool is sparkling clear! all of the stains are gone off of the steps, vertical surfaces and all. a few other minor stains in the bottom of my deep end are gone as well and minor discoloration on my skimmer inlet are all gone. Everything that is supposed to be white is now. Aside from probably paying way more than I needed to for chemicals, they seem to have worked perfectly.

Now for my questions:
1) Can I use CuLator in conjunction with Cal Hypo or would that be pointless (waste of money, incompatible with each other, etc.) ??
2) If only recommending to use one method or the other, which one seems to be better, easier, or produce the best results? (keep in mind my iron issue seems to be minor)
3) If using both together, how do I apply them? CuLator in skimmer sock with Cal Hypo in bottom of skimmer basket? Could I add one to the skimmer basket on pump?
3) If using Cal Hypo, my CYA is low (Less than 20 when I measured), Should I add CYA to bring up to proper levels, and if so when?
4) My CH levels when measured yesterday before starting were 290~300. If I'm letting the CH "float" will it creep up too high for my vinyl pool? (I assume no because of iron attaching to calcium carbonate "dust" precipitate and it getting caught in filter?)
5) How do I know that all of my iron is gone for good, watch for re-staining? If this is the case, how do I address the new stain? repeat process of stain removing and sequestering?
6) What are my options for preventing this in the future when topping off from my well? Aside from filling from my softened/filtered water, use Cal Hypo during that time or CuLator packet?

Also, draining and refilling with metal free water are not options for me at this time. Plus my metal issue seems to be a minor one to me, so I believe it can be addressed using the method you have described and I am willing to give it a try.

I'm sorry if I that's too many questions. browsing here, I see a lot of similar questions being asked and I know it must get tiring to say the same things over and over again. I have tried to search and read older posts regarding this issue as much as possible, but still am unsure about things. I am hungry to learn how to manage my pool and make it look amazing. I'm an engineer by trade, so finding solutions to fix problems is in my blood, I can't help it. So is being long winded sometimes :-/

[PoolDoc]

1. The CuLator packs work very slowly. It won't hurt to have them in the pool, but I'd just suspend them near a return, anytime you are using the cal hypo.

2. The CuLator is probably best for long-term maintenance. Reportedly, it can collect iron that is chelated or sequestered. Cal hypo will not -- though it does have some tendency to 'break' the sequestration.

3. above.

4. Yes, add CYA. Or use some dichlor in addition to the cal hypo. If you buy a 24# pack of dichlor at Sams Club, it will add about 160 ppm of chlorine to your pool, and about 140 ppm of CYA (too much!). If you use the dichlor to quickly rechlorinate, that will immediately add some CYA. The 1# bagged dichlor will keep till next season, which matters, since you won't need it all this year.

5. I have not seen good results from iron testing: I've repeatedly seen pools stained when iron tests indicated no iron. So, yes, you have to wait for the stains.

6. Use a blended strategy: when refilling add a small dose of HEDP chelant; fill with softened water SLOWLY; fill via the skimmer after adding cal hypo tabs to the skimmer; keep Culator packs in the skimmer when not filling.

A couple of points:

=> I do not know that "Natural Chemistry" is intentionally selling products that are likely to produce apparent quick results followed later by failure. But if that WERE their purpose, they are selling the right products to do so. I'd recommend abandoning them as a supplier.

Their chelant is non-phosphate based . . . which means it doesn't add to the phosphate nutrient load and ALSO that it's not chlorine stable. Right now, with the chemicals available to the pool trade, there is a clash between maintaining low phosphates and using effective chelants. It is *possible* to do both, but the situation is not ideal.

What makes it worse is that there is no reliable supplier of plain HEDP (the desired chemical). The closest we can come is the Pink Stuff on Amazon. (Link in the stain sticky).

=> Working out a successful method of managing metals is an individual process, and takes time. I've done it several times on large commercial pools with challenging supply water, but it's always taken me a couple of seasons to get the process tweaked 'just so'. If there's an optimal one-size-fits-all approach, I haven't found it yet.