Looks like Yellow Mustard...but won't brush off

[sr1125]

Hi,

I have been lurking on this board for a while and have learned TONS (oh the things the sales peeps NEVER tell you when you buy a new pool!)

I have a vinyl AGP, 4600 gal rectangular. This is a year old. I have recently developed yellow mustard looking stains on the walls particularly at the seams of the wall and floor. On the walls, they seem to have a swirly pattern to it. However, they won't brush off.

I have tried the Vitamin C (ascorbic acid) tablet against the stain, but it doesn't remove or lighten the stain.

I have shocked the pool over and over. Nothing.

My numbers are:

FC: 3 PPM
PH: 7.4 PPM
TA: 100
CYA: 50

My numbers are pretty consistent, except for the chlorine, which tends to drop to 2PPM (it's been around 100 degrees here), so I add chlorine every other day to keep it level.

Leslies Pool peeps have no idea, tell me to take a picture and bring it in. (Tough to do with a cellphone camera). (Which is another conversation...why their test numbers are sometimes radically different than mine)

Am I doomed to have this ugly looking thing for the rest of my entire life? BTW, my water is/has been crystal clear, and has been since I started using the BBB system.

And ideas would be appreciated. It bugs me to no end to see that when I am in the pool.

Thanks.

 

[duraleigh]

Welcome to the forum. :lol:

Identify the stain. (organic or metals) Hold a trichlor puck directly on the stain for a minute or two and see if the stain disappears or lightens. If not, crush up some cheap vitamin C tablets, put them in a sock, hold them down onto the stain for 2-3 minutes and see if that lightens or eliminates the stain. Report back.

 

[Butterfly]

I have shocked the pool over and over. Nothing.

Did you follow the shock process article in Pool School? For CYA of 50, shock level is around 16 to 20.

My numbers are:

FC: 3 PPM
PH: 7.4 PPM
TA: 100
CYA: 50

My numbers are pretty consistent, except for the chlorine, which tends to drop to 2PPM (it's been around 100 degrees here), so I add chlorine every other day to keep it level.
Your FC is too low for the CYA. With 50 CYA you should maintain FC between 4 and 8, and never below 4.

Welcome to the forum

 

[aa62579]

You will probably need to add chlorine EVERY day, not every OTHER day. It never needs to fall below 4 ppm FC.

 

[sr1125]

Ok, I have tried:

Vit C tabs crushed in a sock and held to spot
Chloine puck held to spot for a few minutes.

Nothing changed.

I did increase my FC to 6 last night, I need to test it again tonight, as well as he PH and TA.

The only think I can think of...is I had green algae a monh ago. I used algae remover (3.5% copper ingredient).

I just don't know anymore. I dont want to dump unneccesary chemicals in he pool.

I am hoping the increase chlorine will fade this.

 

[duraleigh]

Stains are either organic or inorganic. They should respond to either the puck or vitamin C.

So, just guessing, but it is very likely your stain is organic and chlorine will fix it but you are not getting your FC high enough. It needs to get up around 10ppm or so to give you the boost you might need.

Secondly, you need to brush the stain with a stiff brush. It may not completely remove it, but it will expose the surface to the chlorine to do a better job.

Last, read "The ABC's of Pool Water Chemistry" up in Pool School.

 

[sr1125]

Thanks for all the advice. I will jump in it this week and give it a good scrubbing, see if I can't loosen some of the stuff off of it.

 

[linen]

Could you post a pic of the stain.

This seems unlikely, since you have a vinyl liner, but since it doesn't respond to either tests could it be calcium scaling? Calcium scaling does not react to vitamin C or trichlor as far as I know.

Do you have a recent CH test value?

 

[sr1125]

Just did the CH test: 13 drops x 10 = 130.

Todays' readings:
FC 5
PH 7.4
TA 90
CYA 50
PHOS: 250 (not sure if I did this test right...still learning to read this one)


Pictures are next to inpossible, I only have my cell phone camera, while I can see it clerly, thru the lens, not so much.

My other issue is keeping chlorine. I add according to pool calculator, I test if, all look well, then the next day, I'm down to 2.0 or 3.0 ppm. Yet I have stabilizer. So its burning quite fast, and it hasn't been that hot the past week. NUns I need to switch to liquid chlorine 12%???

 

[linen]

With those test numbers, it shouldn't be calcium scaling. How are you getting you test values?

Phosphates can be ignored in a properly chlorinated pool...but how are you getting your phosphate number?

My other issue is keeping chlorine. I add according to pool calculator, I test if, all look well, then the next day, I'm down to 2.0 or 3.0 ppm. Yet I have stabilizer. So its burning quite fast, and it hasn't been that hot the past week.

Where does your FC start at in the morning after adding your dose of chlorine?

I need to switch to liquid chlorine 12%???

What are you using now?

 

[sr1125]

I add the chlorine in the evenings, I don't test till I get home at night.

Using chlorox blue label plain old 6%

 

[linen]

What FC level do you dose to in the evening?

I need to switch to liquid chlorine 12%???

Using chlorox blue label plain old 6%

Chlorine is chlorine, you just need to adjust the poolcalculator.com to reflect the percent sodium hypochlorite you are using.

 

[sr1125]

I get my phosphate test results from a phosphate test kit. I dose to 5 or 6 ppm for chlorine.
I am using a leslies dpd kit ( need to get a fas kit, just looking for something I don't have to match colors with).


Would it hurt to use an ascorbic acid wash to try and clear this stuff? I just noticed it seemed to be slightly sticky at the water line ( or I am imaging it) it won't come off with my nail.

 

[linen]

I dose to 5 or 6 ppm for chlorine.

So your FC is dropping by about 50% during the day, which is not unheard of. Is the pool in full sun? Do you have a lot of organics getting into it (leaves, dirt, etc.)? Lot of swimmers?

I am using a leslies dpd kit ( need to get a fas kit, just looking for something I don't have to match colors with).

Then the FAS-DPD is a good one since you are looking for a color change from pink to clear...very easy to see.

Would it hurt to use an ascorbic acid wash to try and clear this stuff? I just noticed it seemed to be slightly sticky at the water line ( or I am imaging it) it won't come off with my nail.

That is what vitamin C is. You could try having the sock of the crushed C sit on there longer. A picture might really help here...if it is decent.

 

[sr1125]

So your FC is dropping by about 50% during the day, which is not unheard of. Is the pool in full sun? Do you have a lot of organics getting into it (leaves, dirt, etc.)? Lot of swimmers?

The pool is in full sun from 11-4PM. There are trees nearby, but I have a mesh net, so very little gets in. what does is easil;y vacuumed up. and I run the vacuum every other day for about an hour. So I have nothing 'sitting' in the pool. It is in daily use, by myself and 2 kids. Not overly heavy use.

The vitamin C in the sock didn't work I will try and take another picture, but I don't think it shows at all, because I probably need an underwater camera to get something decent.

 

[sr1125]

Update: I decided to use a stain remover in the pool, just to see if it would work or not (the slow slow acting kind).

I had lowered my CYA to 30, then dropped chlorine to 2PPM per instructions, dumped the stuff in the pool and let it filter 24 hours.

A week later, I noticed...it was gone from the pool walls, and there is a significant lessening of the discoloration on the bottom floor/walls.

So I am thinking...maybe another dose for good measure.

What I am not sure is...do I need to add metal remover chemical (can't remember the name off the top) after I totally clear out the yellow-y stuff from the pool (assuming a 2nd dose is going to work)? At this point, I'm not even sue if it was a metal issue or not, but the walls are blue again.

Thanks for all the help on this, the pool doesn't look so...ugh now.