Anyone know what this is? Mustard?

[TyroBullmastiff]

image | nicolemclemore | Flickr

Hello, I finished a 2 1/2 week slam about a week ago & got the pool
crystal clear, passed overnight test. Now this appears in the bottom, only on one side, won't brush off? Any suggestions? It's not sand, & it's in the sunniest part of the pool so could it still be mustard Algee? Help please! Our house goes on the market this week!

 

[OTPirate]

It may be an iron stain. Try rubbing a vitamin C tablet directly on the stain and see if it erases it. Here is an article on identifying stains Pool School - Metals in the Water and Metal Stains

 

[TyroBullmastiff]

Awesome! Thanks! I read through that & will try today! Appreciate it!

 

[TyroBullmastiff]

My #'s are BAD & I'm all confused!
FC-barely turned pink, so .5?
CC-barely turned pink, so .5 as well?
PH-bright yellow- not on chart?
TA-added added 5 drops R008, turned pink not green?
What in the world? I slammed it right I know. U guys helped me do one last year & I did very well. No problems after slam. I switched over to Triclor after slam b/c were not living in the home anymore. Where did I mess up? I think hubs added some algecide for prevention after the slam I'm getting ready to do the puck & vitamin c tests on the stains. Water is still CLEAR as can be!

 

[mknauss]

Your pH and TA have crashed. Most likely from puck use.

Read Pool School - Recommended Pool Chemicals and look at the Raising pH section.

 

[TyroBullmastiff]

Thank you! Ugh! I need this stain gone in 5 days! BUT I cannot do another slam b/c we're not living in the house & I can't get here twice per day to test! Any recommendations? How much borax should I add? Are my levels 0 based on the testing? What do I need to bring them to? What FC level? Shock level? Please help!

 

[mknauss]

Use PoolMath. Assume your pH is 6.8. I see no volume for your pool in your signature so you will need to do the entry into PoolMath.

Target pH of 7.5. It will show how many ounces of soda ash to add.

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You asked on shock level. Do you have algae? You should for now just add chlorine to get to target level [FC/CYA][/FC/CYA]

 

[TyroBullmastiff]

Thank you! I will add the borax. The puck did show organic material so I need to slam correct? I'm just not sure if slamming will work with only being able to text once per day? Thanks so much!

 

[mknauss]

Organic material means SLAM Process

You would be hard pressed to successfully perform a SLAM Process testing once per day.

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Also - depending on what Algaecide was added, they can greatly increase your chlorine demand and cause low FC until you have added gallons of bleach.

Check to see if it was ammonia based. Real mistake if it was. Only one accepted by this forum is Polyquat 60.

 

[TyroBullmastiff]

Will do! Thanks so much!