Semi-transparent patches floating on water

[Jjnol]

We recently purchased a home with a 23,000 gallon in-ground vinyl pool (Hayward) with a sand filter. All-in-all the pool appears to be fine with crystal clear water and based on frequent testing the water chemistry appears good. The only two factors of concern chemically are that the water hardness is low (I'm working on that) and the test strips that test for such things indicate that the stabilizer is on the high side. I've never added stabilizer so I've no idea why this would be.

My primary concern is that we are getting these semi-translucent thin patches of stuff floating on the surface of the water. They have a texture to them and at first I thought they were some sort of insect eggs but clearly they are something else. They are visible only looking at the surface of the pool from an angle in the light otherwise the pool water is perfectly clear. The pool is some years old but has been well cared for by the previous owner.

Online I'm reading about white paper mold but this stuff is only on the service of the pool nothing no note when submerged.

I've been using two variants of shock normally 2 pounds at a time -- sodium dichloro-s-triazinetrione 58.2 percent and trichloro-s-triazinetrione 53.5 percent. These are probably the same thing with slightly different names.

Since the instructions say one pound to every 10k of water I've been rounding down for our 23,000 gallon pool. Maybe I should be rounding up.

Anyway, with the off chance that I've not super-chlorinated it enough I'm going to add 3 or 4 pounds tonight to really kick the water in the butt.

Any suggestions for what could be causing these floating patches?

Thanks for sharing.

Justin

[Watermom]

Hi and welcome to the Pool Forum!

You really need to get a good kit. We don't put faith in test strips and the CYA test strips are especially bad. The kit we recommend is the Taylor K-2006 or 2006C (better buy) that you can get through the test kit link in my signature below.

We really need to know your CYA level to be able to give good advice since needed chlorine levels are based on the CYA reading.

By the way, a vinyl pool does NOT need calcium even though pool stores like to tell you that they do so they can sell you stuff to raise it!

[Jjnol]

Sigh, I've self educated myself on this pool and it's care since buying the house at the end of last November. The pool was covered all of winter with a badly torn pool cover we were afraid to remove until about the last week in February only because I had to find out what kind of mess to expect.

Fortunately the previous owner is a chemist and told me he would shock the pool the best way he knew how and that would mean using an extra strong shock formulation containing mercury.

Well that worked I guess because not one hint of algae but we had to fish out a lot of leaves at the deep end corner leaving it a bit stained. After that I've pretty much got it looking pretty damn good. I do something with the pool daily and we've spent lots of money on chemicals and supplies and yet have been in the pool a grand total of two times.

I've got THREE test kits. Two are strip based and one is the traditional, time consuming, hard to read chemical based kit (pool master basic 5). I use the chemical kit to cross check the strips in Minority Report style just to be sure what I'm seeing is sane. I'm fairly certain I'm getting lucid results for the 5 standard metrics.

Exotic stuff no. For instance CYA is not striking a chord with me. I work with two folks that used to do pool maintenance for a living and other then suggesting the clear spots floating on the surface of the water are a result of low hardness they have no idea what I'm looking at.

Happy to do yet another test kit but a kit the gives me colors to look at that are so close to looking the same is worthless to me. The chemical kit I have is like guess work because the clear pinks and yellows are so close you never feel confident you are reading it right. The strips at least give better discrete colors but I'm sure better kits are out there.

Happy to contribute to your forum if that's what it takes. I would have preferred to know it is a fee for service site before I did that. I've keyed in complete and valid information on who I am and that I'm not a spammer but I'm finding the approach taken for 'new members' both obtuse and, seriously just being frank and not meaning to offend, the new member process is a tad on the passive aggressive side. After doing everything I needed to do to get an 'account' (such as it is) there is really nothing I can do but reply to your response and visit links to pay or buy something.

I'll consider another kit and find out what CYA means as a pool care acronym I suppose. It's just this exchange has not been helpful and I had high hopes it would be.

Thanks for the response. Spending money here might be a good thing to do. Just not sure at this point.

Justin

[PoolDoc]

Fortunately the previous owner is a chemist and told me he would shock the pool the best way he knew how and that would mean using an extra strong shock formulation containing mercury.

There are NOT pool sanitizers or products containing mercury. I've encountered some brain-dead chemists before, but if he really put mercury in your pool, that would certainly put him at the top of the list of crazies!

This SERIOUSLY concerns me; levels of mercury that are toxic to plants are likely to toxic to humans. You really, really need to find out EXACTLY what he put into your pool. Untill you do so -- and have verified that what he put in is not a danger to humans -- DO NOT SWIM IN IT!

I'm hoping "mercury" was a misunderstanding or a typo. If it wasn't you may not only not be able to swim; you may not be able to drain, without hiring very expensive HAZMAT remediation. Do NOT run out and drain it, in hopes you can do so without getting caught. Depending on where you drain and what he put in, you could face criminal charges if you do so!

I'm modding this in immediately, so Chem_Geek can take a look.

[Watermom]

Happy to contribute to your forum if that's what it takes. I would have preferred to know it is a fee for service site before I did that. I've keyed in complete and valid information on who I am and that I'm not a spammer but I'm finding the approach taken for 'new members' both obtuse and, seriously just being frank and not meaning to offend, the new member process is a tad on the passive aggressive side. After doing everything I needed to do to get an 'account' (such as it is) there is really nothing I can do but reply to your response and visit links to pay or buy something.

I'll consider another kit and find out what CYA means as a pool care acronym I suppose. It's just this exchange has not been helpful and I had high hopes it would be.

Thanks for the response. Spending money here might be a good thing to do. Just not sure at this point.

Justin

Justin,
This forum is not a "fee for service site." The only reason I suggested that you get that particular kit is because it is simply the best kit out there that gives you the best information for you and us to be able to help with your pool. The forum does not sell the kit. The kit is not available anyplace locally and the link below takes you to Amazon. Although, each purchase does give a slight percentage to keeping the forum up and running, you do not have to buy the kit at all if you prefer not to and there will still be somebody here who will try and help. There is NO fee required at all on this forum. None of us that help get paid. Period. We do so simply because we like to help pool owners. As far as the new member registration process being "passive aggressive," it certainly is not meant to be. We have had a lot of issues through the years with spammers and hackers trying to cause problems for the forum and it is simply a way to try and keep the forum safe for our members.

I'm sorry that my reply was not helpful to you. I was simply trying to get some additional information to be able to better advise you. I think if you will stick around, do some reading here on the forum and especially the stickied threads at the top of each subsection of the forum and also on our sister website www.poolsolutions.com, you will learn a lot about being able to take care of your pool easily and inexpensively.

Good luck and hope you have an enjoyable swim season.

[chem geek]

I seriously doubt the chemist put anything with mercury into the pool. He probably said something like adding an algicide with metals in it, maybe even saying "heavy metals" so that probably means copper. If you can still contact him, then ask him EXACTLY what was the "extra strong shock formulation containing mercury".

[Pappy]

I don't know how accurate they are, but you can buy mercury test strips on Amazon for about $20. I think if I were in your position, I'd spend the money and be for SURE.

[Jjnol]

Yep, just checked. Copper not mercury. I was not thinking about the ramifications mercury would have. My mistake. I have ZERO concerns about the SAFTEY of the pool. It completely passes the open eyes test with no burning or irritation, no smell of chlorine at all. Test strips and old fastened mix and match kits agree the water is OK. My niece and nephew (allergic to about everything) have had zero issues swimming.

I suppose I just need to let the issue go until I come across an answer. I may have a profession water chemistry done to be sure. But with all the snow this winter, and rain (more then we've ever had in the winter in NC) there is probably not a drop of original water in that pool. We just had 4 more inches day before yesterday.

I'll stop worrying about the almost not visible floaters for now. Didn't mean to kick up all this dust. Thanks for the concern.

[PoolDoc]

That's a relief. I have encountered some pretty horrible recommendations over the years by 'chemists' who were not water treatment specialists, so you really scared me. For what it's worth, mercury contamination would not necessarily have been irritating.

On the other hand, copper stains pools. If that's a concern (it doesn't bother everyone), you'll need to be cautious as you add chlorine.

Regarding your original comments:

+ CYA is one of the most critical measurements on an outdoor pool. It's very difficult to manage an outdoor pool correctly without knowing this. Most algae problems come because people do not understand that chlorine levels have to be determined based on your CYA level. Of course, some people get lucky, and do the right thing by accident. If you are naturally lucky, that's always an option.

+ Low hardness does not cause 'floaters'.

+ Dichlor and trichlor are 2 different chemicals. Both are forms of stabilized chlorine, but have somewhat different properties. The percentages you list don't correspond to undiluted products, so I'm guessing you are buying one of the diluted forms of those products. Dilutants can include borax (harmless or even helpful), magnesium sulfate (harmful to your pool), aluminum sulfate (mostly useless, but potentially harmful to concrete pools), copper sulfate (effective algaecide; effective staining agent) and so forth. You can check the "available chlorine %" to be sure. Trichlor should be 89% or higher available chlorine; dichlor should be either 56% or 61%.

+ Regarding the patches themselves, I have no idea. I can't recall ever seeing anything that would fit that description, but it doesn't sound like you could get a photograph of them. So I can't help with that.


Good luck!

[CarlD]

Is it possible the patches are some sort of debris from the falling-apart winter cover? Sometimes plastic products seem to be multi-layer with a clear layer. It's just WAG on my part (Wild-"Artistic" Guess).