Preventing Metal Stains - Advice/Clarification?

[skinsfan44]

Jason- I found this thread after searching for metals in the water- we just had a new liner installed and had to refill with water loaded with iron .

You mention that you prefer sequestrants based on HEDP, like ProTeams Metal Magic, and you suggested to lower the PH to 7.2 before using.

As I expect the water fill to reach my skimmers later today, I am ready to throw in a few quarts of the Metal Magic when I get home tonight. However, the directions say the PH should be 7.5 to 7.8... more to the high side and the opposite of what you suggest, 7.2.

I am confused what I should be doing with the PH before I throw in the Metal Magic. PH high or low? Any clarity or advice would be appreciated.

As a side note, I set up a whole house filter on my garden hose before filling. Judging my the 4 completely stained filters I have lying next too it, it definitely helped remove some of the iron, but a ton still made it into the pool. I guess I should have sprung for the 2 micron filter instead of the 5 micron Sad thing is, this is not well water. Nice to know our town gives us clean water to drink/cook/bathe with

 

[skillset]

This is confusing! Even though the bottle says Ph neutral, Metal Magic always lowers my Ph a bit, so I have a hunch this is why they want you to start with a higher Ph.

I have used Metal Magic all summer and for me it keeps the metal stains away longer at a lower Ph.

Higher Cl and higher Ph causes metals to fall out of solution, but for me lately, the pool can take the higher Cl. It's the higher Ph (7.5+) that the stains begin reforming.

 

[VaEquestrian]

I can tell you that, as someone who's fought with tea-colored water for several seasons (we have well water), whenever I've put in the sequestrant with the higher PH, it has NOT worked as well, if at all. Every time I've lowered it to at least 7.2, it has worked very well, for longer periods.

Personally, I would not put a seqestrant in water without lowering both the PH and the chlorine. I usually let it filter and mix for several days, then I slowly start bringing up the chorine.........after the chlorine is good (and still no staining), then I bring up the PH. This has worked very well for me.

 

[skinsfan44]

This is confusing! Even though the bottle says Ph neutral, Metal Magic always lowers my Ph a bit, so I have a hunch this is why they want you to start with a higher Ph.

I have used Metal Magic all summer and for me it keeps the metal stains away longer at a lower Ph.

Higher Cl and higher Ph causes metals to fall out of solution, but for me lately, the pool can take the higher Cl. It's the higher Ph (7.5+) that the stains begin reforming.

Thanks skillset. What you said makes sense. Everything I have been reading agreed with what Jason said- lower the PH to help remove metal stains. I just got confused when the Metal Magic arrived last night and said to jack up the PH.

Other than my fiberglass steps steps being a bit brown, I really do not have stains yet (liner is 3 days old). But, after the refill, my water does have a serious brown tint to it so I want to get it under control before any staining of the new liner can occur. I was under the impression that the Metal Magic would not only remove stains, but also allow me to filter out the metals, which I thought would be better than just sequestering them. Maybe I am just falling for marketing hype and the iron will not be filtered out- we shall see

 

[skinsfan44]

Personally, I would not put a seqestrant in water without lowering both the PH and the chlorine. I usually let it filter and mix for several days, then I slowly start bringing up the chorine.........after the chlorine is good (and still no staining), then I bring up the PH. This has worked very well for me.

Thanks VaEquestrian- That is how I will proceed.

As a new fill, I expect the chlorine will be next to nil. I'll make sure the PH is in the low 7's before pouring in the Metal Magic. Do you usually let the pump run on circulate for a while after you use the MM, or is filtering it right away the way to go?

 

[skillset]

I have tried a lot of sequesterants this season - I've had a lot of staining w/my pool. Metal Magic has clearly worked the best. It removes the stains and keeps them away for awhile. But, I don't believe for one second it filters out the metal, as claimed by the product. If it did that, ProTeam would make a fortune! After all, who wouldn't want the metals out - why would anyone buy just a plain old sequesterant that "just" keeps the metal in solution!! I really don't know how they get away with making such a claim. Anyway, I'll contine to use the product. Just ordered a case from Pool Geek as I just ran out.

I saw your other question. I don't believe you need to have the pump on circulate - just normal filtering should work fine. I usually run my pump 24 hours after putting MM in.

 

[JasonLion]

Metal stains are most likely at high PH and high FC levels. At low PH and low FC levels the metals will often stay in the water even without sequestrant. You want to keep the PH fairly low prior to adding sequestrant or you can start getting stains right away. Once the sequestrant is in the water you want to raise the PH and FC levels very slowly just at first. You keep the initial rise slow so you can catch stains right away and add more sequestrant before they become serious.

All of the HEDP based sequestrants are somewhat acidic, which means they will lower the PH. When used at standard dosages the PH change is usually fairly small, typically around -0.1. Larger doses will result in more substantial PH changes (depending on your TA and borate levels). If you anticipate adding large amounts of sequestrant, you might not want to take the PH all the way down to 7.2 before adding sequestrant, so the PH doesn't get too low after adding sequestrant.

I am not sure why Pro Team is suggesting higher starting PH levels. My experience is similar to VaEquestrian's, lower PH levels seem to work better.

 

[VaEquestrian]

If it actually took the metals out, then one would not need to keep adding a "maintenance dose" periodically. So no, I don't believe the metals are filtered out.

I usually just filter normally for a couple of days.