Could this just be a stain???

[phreespirit]

I have been pretty convinced that I have mustard algae and not pollen due to how it clings to the walls. I have SLAMed and then SLAMed at mustard algae target level of 24. Have been scrubbing the walls at least 2x per day. I initially thought it was working because there were little areas of dead algae and a disruption in the algae pattern. Today I am less enthusiastic as it doesn't look much better overall. I'm wondering about taking FC back up to mustard shock level or if that's not good for the equipment etc. Had battled this issue the end of last year with hundreds of dollars of algaecide, etc. Opened the pool on 5/8.
Before mustard algae SLAM:
5/9
FC 11.5
ph 7.2
TA - 90
CH - did not get reading, but was 120 the day before
CYA - 40
5/10
AM read: FC 24
3pm read: FC 21 (added 1 gallon of chlorinated liquid)
7pm read: FC 24
5/11:
FC - 13.5
pH - 7.3
TA - 100
CH - 150
CYA - 35

Appreciate your wisdom!

 

[mknauss]

Looks like copper.

See Stains in Your Pool

 

[phreespirit]

Holy Xmas, I can't believe I didn't think of stains. I live outside of spokane and we definitely have iron in our water, turns toilets orangish. Last year I also put a bunch of algaecide in trying to resolve what I thought was the mustard algae issue. What a 'doh!' moment. I'll take water in and have them test it for metals. Oy vey!

 

[mknauss]

Water may not have metal in it. The metal is deposited on your pool surface.

 

[phreespirit]

My copper is .2 and iron is .1 i bought ascorbic acid and will attempt to treat stain with that.

 

[phreespirit]

You were right. Worked in seconds. I can't believe all the time and money wasted! Thank you!

 

[mknauss]

To remove the iron removed you should drain the pool and refill with fresh water.

Be careful draining Fiberglass pools.

See Draining - Further Reading