Removing calcium/hard water stains that AREN'T in pool.

[y_not]

Forgive me if I have missed this somewhere in my searching.

With that said, what products have any of you successfully used to remove those white, scaly, hard water stains from pool equipment, water lines that refuse to clean, bathtubs, showers, tile, whatever.
Things like CLR and "Some dude's magic this/that.." come to mind. There are products by ZEP and just about everyone out there.

I have various hard water challenges around here.
One example is: glasses left out for days on end that are repeatedly used for drinking water will build up a white scale that's impossible to completely get rid of.
I have let undilute 20 baume MA soak in them with only some impact. The same on our fiberglass showers. Even back when they had brand spankin' shiny new gel coat 15 years ago, it started right away and couldn't get it off.

I have some used pool equipment I bought that has the same junk on it... I think. Looks like it.

Any ideas what actually works on these minerals that are left behind when the water evaporates, ones that seem to be attached like they're bonded and one with the surface?
Maybe I'll have to resort to a soda blaster... but I'd like to avoid that expense for the time being.
Any advice, recommendations would be great!! Please do try to state what you have used it on.
Thanks!!

 

[Richard320]

Well... when I tiled the shower at my last house, I chose rough-textured Calcium White tiles and Mildew Black grout. Seriously! It really cut down on the cleaning.

If MA doesn't cut it, I can't think of anything else that would.

If you ever do get things fairly clean and smooth, you can apply Rain-X for car windshields to the shower. The water just rolls off, it doesn't bead up and leave spots.

 

[y_not]

HAHA!
You would do that. Doesn't surprise me one bit Richard. lol
Only problem is, the stuff's still there, you just can't see it. Ya know?

Cool tip on the Rain-X. Have you actually done it?

Ps. My bad on not putting this here 'coffee bar' in the 1st. place. Seems like I sometimes just have no clue as to where things go.

 

[y_not]

I have been doing some research and found this.
themanlyhousekeeper.com/2011/03/11/solved-soap-scum-and-hard-water-stains/#comment-171896650

It looks like Bar Keeper's friend in cooktop cleaner gel or powder form wins out over COR and Lime Away, among others.
They say to use a no scratch abrasive pad on glass and a MrClean magic eraser on fiberglass/acrylic.

Apparently the primary ingredient is derived from rhubarb, oxalic acid which attacks calcium.
What do you think Chem geek?

I'm going to buy some, try it and report back.

 

[chem geek]

Any acid will dissolve calcium carbonate -- the stronger the acid, the faster the dissolving. The issue is what then happens with the excess calcium you have dissolved. With oxalic acid, you can form calcium oxalate which is a precipitate and apparently it doesn't stain or bond to the plaster so remains "loose" which means you can filter it out or vacuum-to-waste. See this thread. It's probably a decent calcium reducer, though will form a cloudy precipitate.

 

[y_not]

Good stuff Richard, I'll take a look at it later on in the week/tonight.
But the issue isn't so much dissolving the calcium, it's apparently the other "white stuff" in the water deposits that won't go away. Something that pure 20 baume MA won't remove.
Any ideas what that is?

Any experience with a soda blaster? I have been considering buying one.

 

[chem geek]

If both calcium and phosphates are very high, it could be calcium phosphate (there are several types). See this thread. Of if sulfates are very, very high (thousands of ppm), it could be calcium sulfate, but I think calcium phosphate is more likely, especially if the pH got too high at some point.

 

[y_not]

Interesting read Richard. I love your writeups uncovering the hocus pocus of the pool chemical industry. It puts a smile on my face, knowing that through the help of gifted scientists like yourself, we are all making a difference.

As for the pool water chemistry, the problem lies in the fill water. Didn't have a noticeable waterline problem or anything like that last year in the 4 short months the pool was up.

What I'm seeing is scale that collects on the inside if a drinking glass where tap water was left in it and evaporated a bit. Scale remaining as the water receded. Thus would be over the course of many days, a week
This is just one example.

I pour straight MA in the glass and it does outgas, fizz and pop for a bit. But that's it, even leaving it in there for a week straight, agitating here and there, it only put a dent in it. Subsequent treatments don't do anything either, not even using a brush on the acid to scrub the sides does anything. It'll remove some, but there's a super hardy layer that stays behind.

 

[chem geek]

The sad thing is, I'm not a scientist. If the "hocus pocus of the pool chemical industry" was due to misunderstandings that only a highly trained specialist with a PhD in chemistry could understand, that would be one thing, but most of what I've worked on is nothing more than what is taught in lower division college chemistry, with only a few exceptions. Some of it is tedious as heck (the original word gets replaced with ****), but it's not advanced chemistry.

The leftover residue you see may not be calcium phosphate then, because it will dissolve in acid though won't bubble. As noted in this link, calcium sulfate will not dissolve in acid unless it is very hot (near boiling). I just find it hard to believe that your sulfate levels are that high. This water quality report for the city of Redmond, Oregon unfortunately has very little detail in it -- it doesn't even show water hardness!

 

[y_not]

You're not a scientist?
Could have fooled me! So what do you do Richard?
I take it you're just into chemistry, huh?

As for water reports, yeah, our city doesn't exactly make it easy to find that stuff. Initially, last year, I had found the well reports for everything BUT the city wells. Close, but no cigar. I can't find those now for some reason.
But I did find this database: http://170.104.63.9/inventory.php?pwsno=00693
Here's the main website: http://public.health.oregon.gov/Healthy ... index.aspx

Those are all of our wells here in Redmond, in that 1st link. They are indicated in the test reports according to the key in the upper left on the "Groundwater/GWUDI Source Details" pg.
On the page that the link I provided takes you to, scroll to the bottom and look under the heading: "For further information on this public water system, click on the area of interest below:". There, you'll find many links to all the various testing data.
I would think that "Latest Chemical Results" & "Entry Point Detects" would be what you're after. Sadly, there's no data under alkalinity... odd??
"Chemical Group Study" breaks down each of the tested categories and lists the test ID num. performed for each date & well #. But there aren't any details of the results for that test ID num. So you then have to look at the big long list under "Latest Chem..". Unless there's some other way to do it that I didn't see.

I couldn't find calcium in the list, nor phosphates. But I think that's because they aren't testing the water that way. Instead, they're just looking for harmful contaminates.
I'll let you look at it and tell me if it has what you need. If not, tell me what element you do need and I'll call the city tomorrow and ask what report contains that.

 

[chem geek]

I'm a S/W engineer/architect, but I majored in physics/chemistry at U.C. Berkeley with 12 A+'s while I was there.

You should ask about calcium (not just total hardness, but calcium hardness) and sulfates (if they test for that). Also ask if they add phosphates to the water, usually as a corrosion inhibitor.