New pool yellow staining tide mark

[Welsh Marshy]

Hi, we have a new pool that’s one week old, during the early stages before using the water started to turn a green tinge. We did water test and no chlorine registered but all other quality seemed fine. Pool supplier company put in algicide and shock which cleared up water. Within days a yellow stain appeared around pool and got worse over the next few days. Nobody used any sun cream, tanning cream or any other creams that are known to react with copper based products. The algicide that was used we believe was copper based.Has anybody got any ideas to give possible causes or solutions to remove please - thank you 

[RDspaguy]

To my knowledge copper does not stain yellow. 

@jimmythegreek, @Pool Clown,  @waterbear, any insights?

[jimmythegreek]

Test the water for metals. Where was the fill water from?  Iron can make a yellowish to oranges tint. Take Vitamin C crushed up rubbed on it....what happens?

[waterbear]

I have a guess. What is your cyanuric acid level? What form of chlorine are you using? (I suspect you might be using trichlor tabs and you don't have enough Cyanuric acid buildup after a week, which is to be expected,  or a SWCG and have not added enough Cyanuric acid) also, does the stain react to chlorine and disappear (pour some bleach on it and see what happens.) If so it's algae. The fact that you had not chlorine in a week old pool  makes me suspect that t the FC is being burned off by the sun because your stabilizer is low. In addition, some algaecides (notiably polyquat) will also kill chlorine.  Yellow stains are either organic, iron, or algae. Iron would come from your fill water and if your pH was high (if the pool is plaster this is most certainly the case for teh first year!),  shocking  could cause staining . Iron stains are most common in fiberglass pools but can also appear on plaster and vinyl. . You really need to tell us more about your pool and post a full set of test results so we can better help you.

 

A few tests to try, hold a vitamin C tablet on the stain. If it disappears in about 30 seconds where the tablet sat then it's iron. Pour bleach or hold a trichlor tablet on a stain. If it disappears it's algae or organic.

[broberts]

we have a very similar situation.  Our hot tub is only a week or so old.  We filled and ran it with Ahh-some for several hours and got a yellow skum.  Ran it overnight with Ahh-some and got more skum.  Figured we were done, filled with water that had gone through our iron removal and softener.  Still getting more yellow skum.   It is oily so if we try to wipe it off with a paper towel that only works until the paper gets wet then it just smears around.  This morning I tried a paper towel with a bit of olive oil ... it wiped it off beautifully.  Looking at the plumbing there seems no-where that oil could be coming from mechanically.  There is an ozonator and a UV in the system.  No suntan oils.  (No sun today either) 

any ideas where the oil comes from ??