I may be a chemist... but the pool is smarter than I am!

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wetchem

wetchem

0
May 21, 2012
208
Somewhere in the middle of Nebraska
I may be a chemist... but the pool is smarter than I am!

SO, this is my first pool that I get to setup all by myself - YIKES!

Wish I had started looking for setup information and started here... would have saved me some money on chemicals!

SO, Saturday, setup the pool, everything looking good, the kids are excited... yea - then I crush their hopes as the pool isn't full nor ready for swim.
- Sunday, finish filling the pool, to the first checks: pH=7.5;CH=100;TA=hmmm... well, high, very high;Fc=0;CYA=0
- Being a chemist... I went to the store, pulled the pool chemicals out (HTH stuff), targeted around a 6.5 to 7.0pH to drop the TA and added what should have been enough chlorine to shock the pool
- so Monday morning, the pool is nice and clear, pH=6.9; CH=100; TA=well, 300; Fc = 0.63; CYA = 0 (now these were on a dip-strip; however, I tested the water in the lab using a real pH meter and good HACH tests :-D with basically the same results. So, imagine... [after work] walking up to the pool to skim things off and to add more chlorine to the pool... and you guessed it, the water is rust brown. So, suspecting iron I started searching as to what to do about it - found the HTH Metal Control, followed the directions and added like 16oz of the product. The pump has been running like the squirrels chased by my blk-lab, or the kids... for the last 6 hours. I also added another dose of chlorine about 3 hours ago to try and get to the shock levels.

Now, it looks like the rust has started settling out and clinging to the walls of the pool and my current numbers are (as of 23:15 my time) pH=6.8;CH=100;TA=between 180 and 240;Fc=10; CYA=0 (need to find an old sock as I do have the stabilizer). I'll pull another sample in the morning and run it in the lab to see where things actually sit.

As for the iron... I've a hunch that I need to purchase a brush or something to get this stuff off the pool? I think the pool is winning! :hammer:

Am I at least going in the right direction ?

-wc
(yes I get the joke... if you saw the color of the pool this afternoon, sigh)
 
Sometimes it looks the worst when you have it on the run. Read over pool school (link in the upper right of each page), everything will likely be settled soon. :)

Anyway hang around and let us know how it goes, ask for help if you need it, or just share in the fun

Ike
 
It may look terrible but it is a good sign, the iron is precipitating out of solution and can be vacuumed out. However if you have the standard Intex pump and filter set up, it may not be up to the task. You don't want to vacuum to waste unless you can re-fill with an iron-free source of water. In the long run you may be happier if you invest in the intex pump and sand filter combo. It has a stronger pump and much greater filtering capacity than the standard Intex cartridge filter.
 
Isaac-1: Thanks for the vote of encouragement! It was very dissapointing to come home to the brown water. What I don't understand, is why it turned brown when it was clear Monday morning... I understand that some chemical reactions can be fairly slow; however, I wouldn't have expected it to be that slow.

Zea3: My wife had talked to one of her friends and they had apparently upsized their pump too. I have also read a few other posts on other sites talking about putting a sock over the return and an old t-shirt in (around... like a sock) the intex skimmer basket to help catch what the filter is missing. I'll have to talk with the wife and find out where they purchased the pump from. We purchased the pool last year on sale from Target...

BTW: Could you point me in the right direction to start looking at the sandfilter pump?

So for this morning's pool saga:
Ok, so I let the pump run overnight... say 10 to 12 hours. The water looks like tea. Last night I took an old long-bristle broom and "swept" down sides very carefully and as much of the bottom as I could reach.
the chemical report is:
pH=6.95; CH=100; TA=220ish; FE=7.0. - Pretty close to last night's numbers - looks like I might need to add more chlorine.
I also ran the same sample for some metals.. Both sodium and calcium were off my charts however I expected that; magnesium=8.369ppm; copper=0.0; IRON=0.194ppm - for those that know... these are "as is" from the pool this morning analysis by F.A.A.S. (flame method).

- AND -
Before I forget!
THANK YOU one and all for the encouragement and for letting beg/borrow/steal from your experience!

-WC
 
High levels of chlorine can have an effect like high pH which cause metals to percipitate out of solution (remmber chlorine is an oxidizer so it may have converted the free Fe ions in the water into iron oxide/rust, which is much less soluble in water) in some corner cases people have described it as if bleach turned green or brown as it was poured into the water. I suspect you may have hit a supersaturation point and which as you likely know can be related to a number of facors (pH, temperature, etc.) and all of a sudden the invisible metal in solution suddenly percipitated out.

Ike

p.s. I just looked at your numbers, I asusme you mean FC not FE, also I am not sure what to make of the Magnesium amount, in particlar its solubility, oxidation potential, etc.
 
I was just in Lowes buying Stabilizer an hour or so ago and saw they had the same style of Intex sand filter combo with their pool accessories and chemicals, I did not look at it closely, but I think the price was less (I know it was under $200, may have been $199, $179 or $169)

Ike
 
zea3 said:
It may look terrible but it is a good sign, the iron is precipitating out of solution and can be vacuumed out. However if you have the standard Intex pump and filter set up, it may not be up to the task. You don't want to vacuum to waste unless you can re-fill with an iron-free source of water. In the long run you may be happier if you invest in the intex pump and sand filter combo. It has a stronger pump and much greater filtering capacity than the standard Intex cartridge filter.
Click to expand...
Exactly right in my opinion. Floc can help your filter catch it too. I find if you over fill then you can vac to waste the precipitate. Expect to fail the 1st time when you lose too much water.
 
Yes... it should be FC; sorry, I don't know why I typed "FE" instead of "FC" .... must have Iron (Fe) on the brain, need a sand filter for that too! :)

Wow and those are not on the cheap side either, that is as much as the pool would cost full price, and a lot more than we paid!

OK, I turned the pump off while I was at work today. The water was clearer and you could see the brown stuff on the bottom of the pool. I took a careful look at the "vac" that was enclosed... it isn't a vac. It is a backwards facing nozzle inside a "head" that one attaches the garden hose to.

So, what I've done is, for giggles, in the skimmer catch basket I placed a good amount of white paper toweling... turn the pump on and let it run for an hour. The paper is dark-red/brown and the pool is a much lighter yellow brown. So I've pull that out, replaced it with the same amount and added some more chlorine based on this morning's results. I'll let it run for an hour or so and see what happens.

The flock sounds good... I use that in the lab for a lot of different things, wonder where I can purchase some locally!
 
Pool Stores will have floc or clarifier. Most big box stores will also have it. I hesitate recommending floc but in your filter case it's probably a good idea. The issue with those Intex pumps and filters is that they're barely adequate in the best of circumstances and when something goes sideways they are awful. It sounds like the paper towels are helping and I'd continue that as long as you're seeing marked improvement.
 

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Today's results: 7.3pH; 13FC; 110CH; 240TA.
Last night after I added another slug of Cl- we back tracked a tad (well, a lot) with the water clarity which I expected for some reason. So I left the filter run with a new batch of paper towels in the skimmer catch. This morning the water was back to dark tea brown and the paper towels were totally brown almost black… thus switch them out again and left the pump running. BUT – I could see the bottom of the pool!
So, it is becoming very clear to me that I can spend a ton of time with paper-towels, socks, and chemicals to clear up the iron or spend a bit on the sand filter and maybe actually enjoy the pool sometime this year!
Pool store and Big Box stores – for a town of 100K, we are surprisingly small town when it comes to things like that. The only pool store in town closed a few years back; thus, we have a “Super” Wal-mart (that barely carries the basics) and a Menards (that 1/3 of the stuff in the ads are, “… special order at some locations …”). Sigh.

BTW: talked with a chemist-buddy that handles water chemistry for different applications. He confirmed that the reason for the “sudden” change is that I hadn’t quite reached the conditions needed to reduce the iron on Monday, despite having a residual Cl-; thus, when I added the second dose of Cl- that morning to keep the levels up while at work… and then the sun hit the water, the equilibrium shifted to reduce the iron. He mentioned that it would have been very cool to watch it happen.
 
it's for my health };-) the kid's enjoyment is purely bonus.

Tonight, pulled the filter, black... 7.5pH; 4FC; 110CH; 240TA; 0cya via the dipsticks... I know; however, I don't have the lab at home :( wife wouldn't be happy w/me if I did!

Should I bother to put the cya in the pool at this point?
Added another slug of Cl- be nice when the iron isn't chewing away on it.

The paper towels were black too after all day pulling the mud out of the pool. Seems that we're not makeing a lot of progress so we'll be making the hour trip into the "Real" city to look at the sand filter.

Expecting really bad weather tonight so we pulled the poolcover on it
-wc
 
While the sand filter will be an improvement don't expect it to be a miracle. You're doing good by getting as much of the precipitated iron out of the water with the paper towel filter as you can. I know it seems like you're not making much progress but believe me, you are. Even after you get the sand filter, stick with the paper towel filter until they show no signs of iron.
 
Ok, the sample I pulled this morning: 7.7pH; 6.7FC; 110CH; 200TA; however, I didn't get a chance to run it first thing this morning as there were other things to be done in the lab - I've got to get one of those TF100s for the house so I can do tests in the evenings and on the weekend.
So with the bad weather, I left the cover on it during the day... certainly helped to churn the water.
And, as to be expected, the filter and the strainer, and the paper towels were filled with rust. I emptied and rinsed the pump housing because when I pulled the filter out, the rust just peeled off the filter.
-
This evening: The dip sticks gave me back 7.7pH; 10FC; 100CH; 200TA. - seems the pool cover really helped to keep the Cl- in the pool.
-
Looked at the whole house filter, the body itself is quite heavy and of course the inlet/outlets are sized for household plumbing. Looked at purchasing a small submersible utility pump... at $50US plus another $50US for the filter and body, I'm well on my way to the sand filter! :)
Back to the paper towels in the strainer basket! $50 will buy a lot of paper towels and I could get in the pool and just wave them around!
-
 
wetchem said:
Looked at the whole house filter, the body itself is quite heavy and of course the inlet/outlets are sized for household plumbing. Looked at purchasing a small submersible utility pump... at $50US plus another $50US for the filter and body, I'm well on my way to the sand filter!
Click to expand...
That is almost exactly what I did when I had my 1500 gallon intex. It worked great, but took quite awhile to filter it all out. The intex did nothing to filter out my iron.
 
So last night I wrapped a few papertowels around the filter cartridge when changed them out, along with the stuff in the skimmer and I made a long tube with an old cut-up t-shirt and fixed around the return like an old sock and I left the pool cover off.

This morning, went out and did the change it out thing. The tube was just filled with the iron darker near the return outlet and starting to turn rust brown mid way and the pool was much clearer... we're now a nice shade of weak tea moving from brown to yellow. Maybe another month and we can swim... oh yes that sand filter... got to get the sand filter.

This morning: 7.9pH; 10FC; 110CH; 200TA; 0CYA
Added some acid to drop the pH back to the 7.5pH range (hopfully) left everything else alone

-
wc
 

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