'Rust' Spots in Pool

For anything to do with the garden and pool
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Casscat
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Post by Casscat »

Is there a kit that my guy can buy to test for all that teapot? He just has the standard two vial thingy at the moment but is obsessive about maintaining ideal pH levels. The pool is chlorinated.

There is a very large open water deposit on my neighbour's land opposite. He has something like 80,000 square metres of land to tend. I'm sure he'd be happy to have my pool water pumped over to his deposit BUT in exchange he might be persuaded to let me refill the pool from his spring. He is lucky enough to have a spring on his land where I don't. I'd have to refill by tanker if I couldn't get the spring water. However I would hope to avoid having to drain the pool if at all possible.

I will ask John to look for a test kit that will take readings of all the measures you suggest. I would really, really love to think that this is just a water issue which can be easily resolved....
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teapot
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Post by teapot »

Casscat there are test kits available, If your chap can't find a good one (Not dip strips) let me know. Salinity can be checked with dip strips as it's not a fussy level. A professional pool company should be able to carry out the tests for you, any pool company that can't isn't worth a light and should be given a wide berth!

Do check what equipment they use as near me pool companies go "out the back" to test and I have seen dip strips brought out to test with and then the customer charged as if it were a proper test.

The vial thingy, chlorine should be measured using a DPD1 tablet (DPD3 for total chlorine)
If it's the yellow liquid 5 drop jobby, (OTO test) then not really very useful for chlorine levels as that only measures total chlorine and not the free available chlorine for disinfection, The pH side is still fine.

I am afraid I don't believe it's just a water issue although it maybe a contributory factor, it's to minimise the damage/further damage that may take place before you can get to repair it.

That sounds a great plan with the spring water, just make sure you let the chlorine level go down before using it on crops etc, it isn't likely to harm them but people do get upset if they think you may pollute the ground.
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kevsboredagain
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Post by kevsboredagain »

When you need more than the normal tests on the water, your local pool supplier should be able to do this given a sample of water. We have to do this once a year to accurately determine the salt content.
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CSE
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Post by CSE »

If it is the chemical make up of the water causing (which is a probability) of the staining of the pool tiles. Here are some other points for you to think about; did these marks occur after you last had the pool filled/topped up?
Was the water from the same supply as previously used?
If is the chemical make up, then why would there be marks on the side of the pool?
The way these have been described they could be above the height of the normal water line.
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teapot
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Post by teapot »

Kev, obviously down to cost but a saline test doesn't need to be that accurate +/- 250ppm unlike other parameters.

An accurate tester for around £35 or even good dip strips can do this. You'll get several test for that amount.

Provided the local pool supplier has good test equipment. Around me they don't and dip strips are widely used as they can be interpreted by the trained eye to sell even more junk you didn't need. Witnessed it many times. I prefer people to take control of their own pools.

Casa.....steve.
It's not likely to be the outright cause but corrosive water can over time erode grouting and form issues. If the water was perfect when added it changes with chemical additions, use, heating and sunlight so can become corrosive. If the water wasn't perfect and wasn't checked and balanced properly it can cause issues to develop.

Why would there be marks on the side of the pool? The iron on the bottom will dissolve into the water and will deposit on a surface especially if the surface has a pH +8.3, now that isn't the bulk water pH that is the surface of the grout in this case which is traditionally a cement based grout? so any point can have a high pH and rough brushing of the sides/bottom can expose a fresh layer of high pH plaster/grout so that is where it deposits. Given long enough and unchecked all the grouting will go brown from the tiny rust marks on the bottom.

Checking the water now and adjusting the calcium saturation index to make the water passive may help slow down the corrosive effects of the water if it is corrosive (corrosive to plaster not humans).
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CSE
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Post by CSE »

Casa.....steve
:lol: :lol: :lol:

Thanks for the explanation. Questions asked because We are nosey has hell or like to learn things, cannot decide.
Just glad we never wet for a pool, what with H&S regulations plus maintenance. Having too many trees around us and the consequence of falling leaves gives us a good excuse for any guest who asks.
Reinforcement issues come to my mind because of my old work and having seen far too many cockups here in Spain.
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Casscat
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Post by Casscat »

I know I won't know the answer to this until I get the pool water tested, but the pool is filled via town water and well water, both of which are essentially spring water and highly mineralised. Could this explain the staining? The water in my area is famous and there are several bottling plants in the vicinity. It comes to the property untreated.
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kevsboredagain
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Post by kevsboredagain »

teapot wrote:Kev, obviously down to cost but a saline test doesn't need to be that accurate +/- 250ppm unlike other parameters.
We (well the pool man, not me) did that and the results were way off. As soon as the weather became warm the pool went green with algae. The pool shop tested the water and said it was seriously low on salt. Perhaps the strips had gone bad.
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teapot
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Post by teapot »

casasantoestevo wrote:
Casa.....steve
:lol: :lol: :lol:

Thanks for the explanation. Questions asked because We are nosey has hell or like to learn things, cannot decide.
Just glad we never wet for a pool, what with H&S regulations plus maintenance. Having too many trees around us and the consequence of falling leaves gives us a good excuse for any guest who asks.
Reinforcement issues come to my mind because of my old work and having seen far too many cockups here in Spain.
No problem, I don't know the pool rules in Spain but I have heard they go maybe a little overboard on some things. If anyone has the details of the rules for a Spanish pool I would be interested in taking a look over them.
I have a lot of trees beside my pool yet the way I have set out my pool it doesn't cause much of an issue and is low maintenance in the pool sense.
Last edited by teapot on Wed Apr 08, 2015 9:14 pm, edited 1 time in total.
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teapot
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Post by teapot »

Casscat wrote:I know I won't know the answer to this until I get the pool water tested, but the pool is filled via town water and well water, both of which are essentially spring water and highly mineralised. Could this explain the staining? The water in my area is famous and there are several bottling plants in the vicinity. It comes to the property untreated.
It is possible but as you say too early to tell and even with a metals test, once they plate out they don't usually show up, only when in solution can you test for them.

It would be specifically iron or copper, I would be looking at but the rest of the water parameters matter too.
This is iron staining on a liner pool, the clean area to the left is where I have removed the stain before I thought of taking a photo. It covered the whole pool.
Image
Last edited by teapot on Thu Apr 09, 2015 12:50 pm, edited 2 times in total.
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teapot
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Post by teapot »

kevsboredagain wrote:
teapot wrote:Kev, obviously down to cost but a saline test doesn't need to be that accurate +/- 250ppm unlike other parameters.
We (well the pool man, not me) did that and the results were way off. As soon as the weather became warm the pool went green with algae. The pool shop tested the water and said it was seriously low on salt. Perhaps the strips had gone bad.
I am well known for my dislike of test strips as the various manufacturing techniques produce issues, the printers can't faithfully reproduce the correct colours etc but the salt ones I have used, (Palintest and Lovibond) I found to be reasonable but with all these strips, once open they do age very quickly. You may have them left over at the end of the season but discard them. The better more accurate way is titration testing, adding drops or tablets until the solution changes colour is very reliable and I far prefer this method to dip strips
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Casscat
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Post by Casscat »

I have today purchased a large tub of Vit C (ascorbic acid) so all I need is a sock :mrgreen: I do realise that this is not a cure and that the long term solution is going to be painful and expensive, but if I have to stand at my pool edge for an hour proffering a vitamin filled sock in the direction of my rust stains then that will work for me pro tem - hell there are worse places on earth to stand idly for an hour than my pool terrace! Just bring me cava when I start to wilt.....
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teapot
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Post by teapot »

Ok that's good, you need the chlorine level as low as possible so you may choose to add some anti algae treatment to tide you over whilst the chlorine level is low/zero.

The staining in your picture was a small area so you won't need very much in a sock, maybe 50 grams max. Attach the sock to a pool pole and hold it on the stain, it shouldn't take long to remove the stain. Stop with the treatment as soon as possible as the ascorbic will prevent you showing any chlorine for a while, hence why you use this sparingly.
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Casscat
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Post by Casscat »

Timing may be an issue then. I am over there for a couple of days 9-11 May but thereafter the place is booked out pretty solidly and the pool will have to be in tip top shape. Brave souls will want to swim as soon as the air temperature gets above about 28C.
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teapot
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Post by teapot »

Yes that's generally the way it goes :x

If you make sure to buy a source of chlorine, 20 litre biddons of eau de javel are cheap at Brico sheds €12.90 at Brico depot you can use that to quickly raise the chlorine level and burn out the ascorbic acid, just be sure to keep the pH near the lower end 7.2-7.4
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