sudden ring at water level

[rajung]

Well I have been lowering my TA level with acid.Due to 420ppm refill water
My current tests.
FC 4.6 , had it up to 6ppm earlier in the day-8 30 pm right now
ph 7.3
TA 130
CYA 50
shocked pool up to 20ppm 2 weeks ago. after refill from winter lowering
used polyquat 60 when closing pool but nothing since opening.
I started aerating yesterday morning with a fairly large water pump, almost like a small sump pump for the last 24 hours.
Never had this brown/black ring at water level line, most of it is at the opposite side of pool from where the pump is running.
Northern side.
Not sure but seems to even have some light liner fade at the water line at the far end of pool , maybe a inch tall in a small section.
After I added the acid, no more than a quart at a time, about 3 hours apart twice a day I would also brush the whole pool and have pool pump running and the aerate pump running- sudden freak out at sunset.
No one has used pool yet.First time i used this pump to get this much water bubbles.
Maybe too much? does make a lot of current also.The stain is a little hard too see with the crappy iphone, starting to get dark, and I did scrub some already with brush, and magic eraser, did get most off but still a slight dark sticky texture that just wants to smear like an old adhesive, I can scratch it with finger nail but tough to get off
My skimmer is near the pump I put in so maybe the the water isn't getting into the filter to circulate the chlorine? just guessing now.One thing I have done different this year.
I opened my pool and got everything running about 2 weeks ago, last week I installed a timer and had my pool pump running 8 hrs. from 10am - 6pm
Ran it 24/7 before.

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[duraleigh]

Hard to say from your description but, if you have a gasoline powered pump, are you leaking some oil?

 

[rajung]

no
its a submersible, all plastic 1/2 hp utility pump
sure makes PH go from 7.3 or so to 7.8 over night
I see this morning looking out window, the ring is already back but also near the skimmer.I think its keeping the skimmer from doing its job and just circulating the water .
Going to check PH and if its in the normal range , going to remove.
I think I am too worried about getting the TA to around 110ppm, for some reason I felt that was an average good number- but will leave at my current adjusted number of 130.
Never had a PH spike or sudden low reading.always stayed at 7.6/7.4ppm before.I dont know why I felt the need to lower TA but my city water out of faucet is 420ppm which really changes things after spring refill.
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[pooldv]

Most of those submersible pumps are oil filled. Usually a non-toxic mineral oil. I had trouble with those when I had fish ponds.

 

[rajung]

I took pump out today,my PH is at 7.4-and TA at 120
After 6 hours of taking pump out no ring again
What a pain to remove,just used a magic eraser but it wanted to smear more than remove.95% gone
Good thought on pump oil.
water is super clear.
thought I had a good thing going with that pump.
Cant wait to see what the morning shows.originally thought I may have algae starting
last test tonight
FC 4.6
CC o
PH 7.4
TA 120
CYA 40

 

[JasonLion]

Kind of an aside but, there is no real point in doing the FC/CC test with a 25 ml sample so it goes by steps of 0.2. Using a 10 ml sample so it goes by steps of 0.5 is more than good enough and also saves on reagent usage.

 

[rajung]

Kind of an aside but, there is no real point in doing the FC/CC test with a 25 ml sample so it goes by steps of 0.2. Using a 10 ml sample so it goes by steps of 0.5 is more than good enough and also saves on reagent usage.

Thanks,I have tried the 2 different variations of tests with TA- 10 or 25ml and have seen some slight variations one way or another but maybe too small of an issue?
The ring has not re appeared so it must have something to do with oils from pump or what ever could be in the water not getting into skimmer and suspended too long on surface, but just a guess.Thanks for the inputs.Too bad a great fix to quick PH rise caused a mess on clean up.
Just curious,With awful high TA at 420 for refill water, after doing a water reduction for winterizing,the next spring I am sure I will end up bringing the TA back up to 180 something,should I just leave it there if PH stays constant after that?My city water has a PH of 7.4/7.6

 

[rajung]

Just able to do a follow up on this thread, due to some surgery and was looking for some opinions.
I attached another picture from the same area where the sticky slime was.
I do notice now where the liner has faded in the same area as the ring of whatever I had.
Mostly where there was a thicker layer of it, other small section where it came off easy doesn't have fade.So its contained to far end of pool opposite skimmer,Hope liner isnt slowly getting destroyed? 1 year old.
Have no idea what caused this.
current tests, PH 7.3-TA 100-FC 4. CC 0-borate 30-CYA 40
Haven't used pool yet, did use nothing more than a magic eraser while cleaning the area before.
Yesterday I was curious and rubbed pretty hard in one area with my finger right below water level line and I was able to slightly rub some color off,not much but able to, and only in limited spots in that area.Pretty strange how that pump raised PH so fast and caused a ring overnight also.Cant think of what else it could be caused by especially the fade and just at one end, rest looks perfect.

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