Chemical causing 'stains'? Is this dangerous to kids?

just_me

Member
Aug 13, 2007
12
I wrote here a few weeks ago about a cloudy pool. Its cleared mostly- until i put in the aquabot!

Anyway, i saw today that a number of patches are appearing in the floor and on the walls- they kind of look like shadows but are actually stains. I realised one of the issues for cloudiness was because my housemate and i had stupidly added bicarb and calcium sulfate (??) within moments of each other. Is the calcium causing this issue with the staining?

I plan to re plaster come spring anyway but was wondering if the chemicals/chemistry of the pool is doing this to plaster what is it doing to the kids that swim in it?!

I also bought the Taylor k2006c dpd kit thingy and i cant use it! It wont give me readings for chlorine (i know this is high anyway) and Total Alkalinity, i am going to have to take a sample to the pool store again. The water just doesn't go to red like its supposed to, i added the extra neutralizer because of high chlorine but i was just adding hundreds of drops with it not changing!

I never was any good at chemistry :roll:
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
When you do the TA test what color is the water after the initial drops? And, does it change to any other color at any point, even if not red? Also, if you describe what happens with the chlorine test we can probably help you figure it out.

You can start trying to figure out what the stains are by gently rubbing them with a sock that contains a few crushed vitamin C tablets and also rubbing gently with a trichlor tablet and seeing if either of them remove the stains.
 

just_me

Member
Aug 13, 2007
12
with the TA test it got to yellow on one go and a pink on another where i used less water.

The chlorine just wouldnt change. I gave up. I think i need a simpler kit!
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
Just be patient a little longer. You will get the hang of the tests if you give it a few more tries. One thing that is good to try is to test your tap water. That will give you more practice with the test kit and is good to know so you can anticipate what replacing water will do to the chemistry.

At high chlorine levels the TA test sometimes goes from blue to yellow instead of from green to red. Just watch for a color change from the initial color and that is the TA level.

For very high FC levels you might want to try a 5 mL sample, so that each drop counts as 1 ppm.