yellow stain on fiberglass steps and around inlet ports

[duckmka]

I have an inground vinyl pool, approx 30,000 gallons. I switched to the BBB method from Baquacil a year ago and have been quite pleased with the results. One thing I have noticed this year is a yellow stain on my fiberglass steps (bottom one primarily) and also around my inlet ports. It is not an algae type growth as I have scrubbed the steps and the ports with little result.

Any clues as to the cause. My water is very well balanced with PH in the 7.4 range. TA at 90 and chlorine levels also good...

Thanks in advance

 

[whoozer]

Have you had your water tested for metals?? That commonly causes staining.

 

[Guest]

Also, what is your CH? Low CH in a fibeglass pool can contribute to the tendency to stain. This probably applies to fiberglass steps also.
Try holding a vitamin C tablet on a stained area for about 30 seconds. If the stain disappears where the tablet was then it's iron and easily removed. See the ascorbic acid sticky.

 

[duckmka]

Sorry folks...was away and never got to re-post on this...I had my water tested for metals at the pool store and nothing turned up...My CH was on the low side - 170 and I am still getting the yellow staining on my Fiberglass steps..

Any thoughts...

 

[duckmka]

Just to re-cap..

30,000 gallon in ground vinyl
Fc- 2.5
TC - 2.5
Ph - 7.4
TA - 90
CH - 170
my CYA was low and have just added...

i use a DE filter.

 

[JasonLion]

If the metals are in the stains they won't be in the water. Try holding a Vitamin C tablet to one of the stains for 30 seconds and see if the stain goes away in that spot. If the Vitamin C works you can do an ascorbic acid treatment to clear up the stains.

 

[duckmka]

Ok..Thanks.I will try that and let you know the results..

 

[duckmka]

what is the sequestering agent that you speak about in the ascorbic acid test??

 

[JasonLion]

Sequestrants hold the metals in the water so they don't deposit as stains. ProTeam's Metal Magic and Jack's Magic the Pink Stuff (regular), the Blue Stuff (fresh plaster), and the Purple Stuff (SWG) are some of the top sequestrants. You can also find many other brands with similar products, some of which are noticeably less expensive.

 

[duckmka]

Thanks...well problem seems to have been solved on my steps...I used an agent called yellow out and subsequently brought my pool up to shock levels...this overnight turned my steps white again...I am curious to see if this holds or comes back again..I will keep you posted.

 

[New2Me]

What is this Yellow Out that you used, and where did you get it? I have used something like that for treating algae.