Darker spots on marcite

[Coheed]

Hello all! I have had darker spots on my marcite for about a month now (was refinished in April) and am not sure what is causing it. Not sure if that is normal... can also see the lighter are around the drains where they made 1 into 2 and patched the concrete. Have had some pink stains pop up in the same area about the time small algae begins to grow (darn trees over the screen room).

Any and all help is appreciated.

FC - 3
CC or TC - 1
pH - 7.6
TA - 45
CH - 250
CYA - 70

 

[sktn77a]

Looks like the kind of discoloration that develops when the plasterer used too much calcium chloride in the plaster mix. They do this to accelerate drying/curing. The resultant dry trowelling can cause differences in surface properties which produce "stains" like this.

 

[bmoreswim]

Ours has all that and a bag of chips. If it's white plaster, I'm sure it's kind of annoying. Our plaster is gray (marcite with some onyx Diamond Bright mixed in) so it is already mottled and therefore the discoloration like you have isn't as stark and doesn't bother us.

There is an expectation (not unjustly so) that a pool finish will be perfect. And in a perfect world it would. However with imperfect applicators, imperfect water chemistry, imperfect x, y and z, the result can easily be imperfect appearance. Others will likely chime in with some potentially helpful (in understanding the issue or with suggestions) comments - as the above poster did (I realize mine aren't probably helpful). And for that I apologize.

 

[Coheed]

Ours has all that and a bag of chips. If it's white plaster, I'm sure it's kind of annoying. Our plaster is gray (marcite with some onyx Diamond Bright mixed in) so it is already mottled and therefore the discoloration like you have isn't as stark and doesn't bother us.

There is an expectation (not unjustly so) that a pool finish will be perfect. And in a perfect world it would. However with imperfect applicators, imperfect water chemistry, imperfect x, y and z, the result can easily be imperfect appearance. Others will likely chime in with some potentially helpful (in understanding the issue or with suggestions) comments - as the above poster did (I realize mine aren't probably helpful). And for that I apologize.

I appreciate it, I was just wanting to know if I was messing something up or missing a chemical that needs balanced.

- - - Updated - - -

Looks like the kind of discoloration that develops when the plasterer used too much calcium chloride in the plaster mix. They do this to accelerate drying/curing. The resultant dry trowelling can cause differences in surface properties which produce "stains" like this.

Thanks for the info.