A Colleagues Pool

Aug 9, 2016
75
Manorville, NY
Good Day Everyone! Just want to say thank you for the wonderful resource this website is. I hardly even think about my pool anymore. Anyway a colleague of mine has been having issues this past weekend and I had him bring a water sample into work today and tested it this morning.

He went away for the weekend and now there is a green coating on the bottom of the pool that is almost like a stain by his description, it doesn't vacuum up. He can see the bottom.

Basically 2 pool stores were telling him his FC was around 3-4 ppm and they had him add low n slo or something like that and all this other stuff. The end result is test results as follows:

Anyway he has a 30,000 gallon Chlorine Pool, he has had the filter running for 3 days or so straight since he got home and noticed it. He hasn't added any shock or chlorine which makes me shocked about the FC levels I am getting given 2 pool stores told him 3.0 - 4.0 ppm anyway now on to the shocking part (one also told him, a very reputable one I thought, multi million dollar pool builder that his CYA was great at a reading of 129 on there chart, scratch my head).

Test Date
Test Time
FC
pH
TA
CH
CYA
7/31/2017
6:59 AM
30.5
7.9
140
125
85


I had planned on telling him to slam and even draining his pool to drop the CYA. I pretty much figured he is basically already almost at SLAM levels so might as well just slam even with the large CYA. Also the TA is ridiculously high. Anyway with that said I have instructed him to add a jug of 6% bleach tonight and a jug of 6% bleach tomorrow morning, along with adding some dry acid from walmart (about 7 lbs) to get the pH down so the TA starts to drop as well. I am sort of guestimating and making up for the fact I can only test his pool water once a day.

He says the pool is completely clean in terms of no debris at all and I trust him on that. He is 68 and not very good with smart phones so I can't have him give me pictures. If it's still an issue over the weekend when I have the time I will go over there and try to help trouble shoot/test more frequently myself. He is by no means useless so he can pick up this test method once he see's the proof.

Anyway with all that said what does everyone think about my approach. Kind of hard as I am not there to test multiple times per day or do an Overnight FC Loss test, but just trying to work with what I can and help a coworker out, so any input you guys can give would as always be greatly appreciated. I think the green stain kind of thing on the bottom is probably just algae that is somehow stuck on the liner bottom, he said its been there to a lesser extent other times but now its everywhere. So sounds like he has always had algae on some level. Him and his family aren't swimming anymore per my advice until I can at the very least get it looking good and do a successful OFCLT. Just trying to get ahead of the ball so it is pretty much a 2 second thing by the time Friday rolls around. My biggest concern is that CYA I was originally thinking we were going to have to empty half his pool, but with the FC so high I am not so sure, might be able to get things under control and then worry about emptying and refilling.
 
Great for you in trying to help him solve his water chemistry problems.

The pH is not accurate. Please do not add any acid to this pool. If your FC is above 10, you cannot use the drop test for pH.

I would be somewhat suspect of the FC depending on how old the water sample was when he brought it in. But, it would be lower than actual so it is still pretty high.

Is there any way to know what he has added to this pool in the past?

Low and slo is sodium bisulfate. Please discontinue using this and use muriatic acid in the future.

You need to know how the FC is staying that high. He must be adding something.

Take care.
 
Ok just spoke with him too late on the ph down unfortunately. Ugh hope I didn't screw him up even more. He said his pool got cloudy when he got home.

He puts 2 chlorine pucks in every 3 days and supposedly that is it. I should have a picture of exactly what those chlorine pucks are tomorrow. The packaging at least.

As I can not monitor it like my own pool should I have him keep those pucks in at that rate and support the slam with bleach?
 
The information is flying in the pucks are as shown below

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The pucks are, I bet, Costco or Clorox XtraBlue or something like it. The 'other ingredients' are in part, copper.

He could have the start of a really bad copper stain.

I still can not get my head around having that high of a FC. I would have him stop adding pucks for a couple days and bring you water samples to see if the FC drops.

The pH is going to be interesting. The high number you got was effected by the high FC. But, pucks are very acidic, normally we see very low pH when they are used without proper testing and management.

You have a mystery. It will be solved. I would suggest you get him to order his own TF100 and teach him to do his own testing.

Also, he may need to drain a bunch of water if copper is the culprit.

Take care.

TA testing you asked about - no effect on it from high FC. Again, odd to have it that high with the use of pucks. Has he added borax or baking soda recently?
 
Its Chlorox extra blue, and it does have copper in it. Have him take a sample to test for metals, or better yet have him give you the sample and take it to test for metals, since you won't be tempted to buy anything. As far as the chlorine reading, any chance you have a testing error?
 
I see Manorville is on Long Island. How is your fill water? Is it well or utility? High TA, pH?

Thanks
 
Stop using products that contain copper. Then use an additive to lift the stain. Then drain to get rid of it.

We have folks that have quite a bit of experience with metal stains. Once we get more information we will get them to join in the discussion.
 

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Ok I can't get a hold of him but I will tell him to remove tomorrow and I guess just take it to a pool store to test for copper and I'll do another set of tests. If it is copper what should he use to clean it it is coating the entire bottom of the pool if that is what it is or just tell him to drain it then treat the stain with something? Keep in mind it is a vinyl liner pool
 
Ok I can't get a hold of him but I will tell him to remove tomorrow and I guess just take it to a pool store to test for copper and I'll do another set of tests. If it is copper what should he use to clean it it is coating the entire bottom of the pool if that is what it is or just tell him to drain it then treat the stain with something? Keep in mind it is a vinyl liner pool
Like I said, we have some folks on the forum that are really good with stains. We will get them to chime in once you see if it is a metal stain.

One way to check. Get a big bottle of generic Vitamin C tablets. Put them in a sock. Mush them up. Hold it against the stain for a few minutes. If it lightens or removes the stain, it is metal, and most likely copper.

Take care.
 
Ok I can't get a hold of him but I will tell him to remove tomorrow and I guess just take it to a pool store to test for copper and I'll do another set of tests. If it is copper what should he use to clean it it is coating the entire bottom of the pool if that is what it is or just tell him to drain it then treat the stain with something? Keep in mind it is a vinyl liner pool

It may seem counter intuative but you treat the stain first and then drain/refill. Here's why; the stain developed when metals in the water fell out of solution and deposited on the pool surface. When you treat the stain, you are putting metals back into solution. Once the stain has lifted, you drain and replace the water to lower the metal content.

Since your friend has a vinyl liner, they may have to do a couple of partial drain and refill cycles to get rid of enough metal so it is no longer a problem.

Don't be surprised if the test shows low/no copper. If this is metal staining then a good amount of metal is no longer in solution and cannot be measured on the test. If you want to be positive about the source of the stain you can get a Jack's Magic Stain ID kit.
 
Ok here is the latest update. Apparently he did add Shock a few days ago, so that explains why the chlorine level got so high. The test from this morning is as follows:

Test Date
Test Time
FC
pH
TA
CH
CYA
7/31/2017
6:59 AM
30.5
7.9
140
125
85
8/1/2017
6:48 AM
35
7.8
70
-
80


So the TA is at least now under control if that is accurate. The pH level is reading 7.8, but as we have already went over that is inaccurate due to the high pH level.

At this point I have told him to go take his pucks out at lunch. He is going to do that.

He did have a copper problem a few years ago as well that he used the pool store method to get rid of and it seemed to have worked. He had the copper tested a few weeks ago and the levels in the water were insignificant. I suspect it still is copper and it just isn't in the water significantly until we lift it off.

Anyway at this point I have told him not to add any more bleach or any more chemicals just get those pucks out.

He is also going to take some crushed up vitamin C and scrub and see what that does so we get that answer.

My next question is what do we do next. The pool is still cloudy but got a little clearer from yesterday to today according to him. I suspect the reason the pool is cloudy might be the CYA level? Should we even bother doing anything to remedy this or am I off on that and it is likely the pH causing the pool to be cloudy, but we can't do anything about that until the FC goes down?

Will have more info on what goes on with the green stain this afternoon, but just to get ahead of the game if the Vitamin C tablets do take it up and it is copper.

Thanks again for all the help. He just wants the pool clear at this point then to focus more on the copper, but I am not quite sure how to go about telling him exactly what the plan is so that he has some sort of an idea of what it is going to take to solve all the problems.
 
CYA does not make the water cloudy. Normally that is organics or a reaction during the addition of baking soda (to raise TA) or calcium chloride (to raise CH).

How did the TA fall in half in one day? That is not possible unless the water was changed out.

He is way above SLAM level right now. To the point of potentially damaging his vinyl liner. Need to get the FC at 40% of CYA and hold it until the pool is clear then do an OCLT.

You are probably right on the copper - it is in the stain. If he is OK with leaving it there - great. Just do not add any more copper.

Hope that helps -- you are a kind friend to be putting this much effort into his pool!
 
No clue why the TA fell in half in 1 day but no water was added. He added the pH minus, and I have done the TA test 1000x myself, but needless to say perhaps I made some wierd error the first go around and got it right this time. Anything is possible though I don't believe I did.

He just took the 3 chlorine tabs out at noon and I tested the water when he just broguht it back from lunch and the FC is now 32.0. According to the pool math app and pool school the slam level should be 31 as the CYA is 80. Should I have him continue to hold it at 31?

I neverr heard of the FC to 40% of the CYA so that is the only part I am confused with I have always gone by the letter of the law with pool school. Now that the chlorine pucks are out of there I should be able to keep an eye on things better.
 
My math was a little off this AM -- 31 is correct for shock level FC at CYA 80.

The chart is essentially built with shock levels at FC 40% of CYA. You should certainly use the chlorine / CYA chart.

So have him stay at SLAM level FC for a couple days.

When an OCLT needs to be done I would not suggest transporting the water to test it. You are losing a bit of FC during transport.

Take care.
 

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