Stains, but how/why?

ivyleager

LifeTime Supporter
Sep 6, 2007
498
Raleigh-Durham,NC
Imagine my :shock: when I pulled back the mesh cover and found stains. I've never had any metals in my water, and my house water (fill water) was tested YEARS ago and was negative for metals. However, the Vit C tablet test is positive. The only place that doesn't have stains is where the small (2ft diameter) circle of leaves were in the bottom of the pool. I don't see stains on the sides of the pool, just the bottom of vinyl liner and white steps. I don't have a water heater. The ONLY thing I did different this winter was I used a small pool cover pump as NC had a lot of rain and it allowed me to keep pool pump/filter off line (metal from the hose??? - yeah its a stretch).

I put pool pump/filter back online (6hrs/day) about 1-2 months ago when the pollen bloom was just beginning here in NC. Peaked under the cover and water clear, small area of leaves in deep end, dusty debris on bottom of liner throughout (did I mention I have a mesh winter cover?). Initial water readings: pH 7.4 CL 0; CYA 60 (first season I haven't lost CYA, I usually open late April to a green swamp). I've been adding 1/2 lg jug of bleach every 3-4 days and CL holding at 4-5ppm. Last Thursday mesh cover pulled off. What I thought was further "dusty debris" didn't brush off nor come off during cleaning w/ Aquabot. I initially thought it was tannin stains from leaves so increased CL to 15 and waited for sun and chlorine to work to resolve the stain. Didn't work. Then realized they are metal/iron stains. < :grrrr: >

Current water readings(mine......pool store)
pH: 7.2 7.8
FC (ran out of powder) 9
TC 10 (dilution method) 9
TA 70 75; 52 adjusted??
CH 140 134
CYA 60 69
IRON: 0.1ppm

The only significant discrepancy between our results is the pH finding. I'm trusting my readings.

So while I wait for my CL to go down, I picked up ascorbic acid from pool store (2 Natural Chemistry Stain Free - 1.75 lbs.) and their sequestrant Metal Free. At least they told me it was a sequestrant. Only difference in deliver system is product suggests adding Metal Free w/in one hour after Stain Free application. After 24 hrs, then vacuum. Most product reviewer note they didn't add sequestrant for 24 hrs. Sounds about right.

I am taking my fill water in for testing tomorrow to see if it has metal. All household surfaces do not show metal staining....calcium build up yes, but no staining. Curious.

Has anyone here used the Natural Chemistry Stain Free product??
 
So I went back to pools store to have my fill well water tested and results are surprising.

FC 0.18
TC 0.25
CC 0.07
CYA 19
And these 4 well water results just go to show that you really need to rinse out your water sample bottle more thoroughly. :hammer:

ALK 280 yet I struggle to maintain alk high enough. Sits at 70 mostly, and every so often it goes down to 60.
pH 7.5
CH 156
Iron 0 (yet I have iron in my pool)
Copper 0.01 (yet no reading ever for copper)

Finally got around to taking pics of stains. Chlorine is 4 today, so maybe another day for it to decrease to 1 then apply the treatment.

[attachment=0:2iy0zkxa]IMG00254-20120508-1029.jpg-2.jpg[/attachment:2iy0zkxa]
[attachment=2:2iy0zkxa]IMG00255-20120508-1030.jpg.jpg[/attachment:2iy0zkxa]
[attachment=1:2iy0zkxa]IMG00256-20120508-1031.jpg.jpg[/attachment:2iy0zkxa]
 

Attachments

  • IMG00255-20120508-1030.jpg.jpg
    IMG00255-20120508-1030.jpg.jpg
    73.1 KB · Views: 239
  • IMG00255-20120508-1030.jpg.jpg
    IMG00255-20120508-1030.jpg.jpg
    73.1 KB · Views: 239
  • IMG00256-20120508-1031.jpg.jpg
    IMG00256-20120508-1031.jpg.jpg
    86.1 KB · Views: 239
  • IMG00256-20120508-1031.jpg.jpg
    IMG00256-20120508-1031.jpg.jpg
    86.1 KB · Views: 239
  • IMG00254-20120508-1029.jpg-2.jpg
    IMG00254-20120508-1029.jpg-2.jpg
    63 KB · Views: 239
  • IMG00254-20120508-1029.jpg-2.jpg
    IMG00254-20120508-1029.jpg-2.jpg
    63 KB · Views: 239
My FC is taking it's time lowering to <1ppm. Tuesday it was 4 and this morning it is 3. Not much movement. Sure wish it would hold like this during the swim season!

I thought of a possible cause of iron in water. When we took ladder out last fall during closing, there was water inside when we took the rubber tips off and the inside was/is rusty. Could some of that "rust" leaked out into the water during swim season and that's where the iron came from? I am grasping at straws. I feel that I need to figure out the how so it doesn't happen again.
 
Metal Free is not one of the sequestrants we recommend. Stain Free is fine, a somewhat expensive way of buying ascorbic acid.

I recommend using a polyquat based algaecide when doing an AA treatment.

Yes, the ladder could we have been a source of iron in the water.
 
JasonLion said:
Metal Free is not one of the sequestrants we recommend. Stain Free is fine, a somewhat expensive way of buying ascorbic acid.

I recommend using a polyquat based algaecide when doing an AA treatment.

Pool store took Metal Free back and I exchanged for more PolyQuat60. They had nothing else I needed. Had to go to another store for Jacks Magic Pink Stuff.

FC finally zero today (pH 7.4) Even with Polyquat added over the weekend, slight green growth on slope in deep end. Ran pump 24/7 for past 2 days in hopes of fending off algae. Not to be.

Just added both containers (1.75#ea) of Stain Free to circulating water. Slight decrease in staining after 15 minutes. No magic disappearing act yet. Started raining and now can't see the stains clearly. The look to be much less noticeable, but they are still there. Will continue to circulate for another hour.

If stains are not TOTALLY gone, do I add more Stain Free product, or use sequestrant to get the metals currently in suspension?

Not sure what the best course of action is at this point.

Cary
 
Water has been circulating 2 hours now. 95% of the staining is gone, but faint stain still in deep end corner AND transition slope area. Very faint. I don't want to be adding sequestrant when it's dark. I can always come back and run some Vit C tabs on the areas when the water warms up in a week or so. OR should I give the ascorbic acid a bit more time?

Indecisive in Durham......
 
Stains totally gone. Water balanced and looking fine. Pool store testing shows no iron, so all is bound by sequestrant. I utilized DE in sand filter and backwashed several times following sequestrant hoping to filter out the metals. I also grabbed new rubber ends for ladder. Hopefully that will fix rusting of inside of ladder.

AA treatment absolutely worked! Thanks mbar.
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.