Black stain and blue filter

[grisetti]

My first post!

After recently hooking up a Hayward propane pool heater to the system, I start getting black, smudgeable marks above the water line, the white hose from the skimmer has turned yellow, and today I replaced the filter and noticed it had turned blue. Is this from copper? or something else?

Thanks for your help!

Joe



Intex 16'x48" round UltraFrame, 2500 g/per hr pump upgrade, Intex Skimmer, Krystal Clear SWCG, Hayward above ground propane pool heater, Intex magnetic wall light, Flex Head vacuum head with adapter to pool intake.

 

[duraleigh]

Hi, Joe!

Welcome to the forum. :lol:

That's difficult to analyze and might be three seperate issues. I'll tackle the black smudges.

Because it's above the waterline, that sorta' eliminates any water chemistry issues. How do you think that might be connected to your heater? I can't make a connection there. Pictures would probably be a great help in this situation.

Sooner or later you will need water chemistry test results but I still don't think the black smudges are related to water chemistry.

 

[Richard320]

Not sure about the black stuff - any chance it's the rubber hose deteriorating?

If the blue is like this, it's probably copper. Have you used any algaecides? Maybe you should disconnect the copper bars in your SWG, too.

The yellow is likely iron - not surprising, really.... there's got to be a reason your town is named "Ferrum"! The blue might also be Iron Sulfate

 

[grisetti]

Thanks for responding. At first I thought the black smudges may have been the result of ash coming from a nearby fire pit, but when the white paper filter turned blue and I noticed the white hose from the skimmer turn a yellowish color, I began thinking maybe it was related to metal. I had read a few things about copper in the forums and thought maybe that was contributing being that there are copper plates in the SWCG and the recent use of the pool heater, which may have a copper heat exchanger inside (I don't know for sure). I have tested the copper with test strips and it did read a little higher than normal. The water has recently become a little cloudy, so I shocked it today. I received my TF-100 kit yesterday and I am working on getting all my numbers right. Currently my numbers are as follows:

pH 7.0
TA 40
CYA 0 (have sock hanging in the pool now)
FC 4.5
CC 0
TC 4.5

Richard320 - that color blue is the color the filter turned. We are on well water, which I used to partially fill the pool - God filled the rest. I don't have a test in the kit for Iron.

Thanks again.

 

[grisetti]

No rubber hoses in the system.

 

[duraleigh]

What dosage did you apply to the pool for the CYA? 30 ppm? 40 ppm?

What have you done to try to remove the black smudges? Got any pics?

I still think the smudges are not water chemiostry related......you may remove them and never know.

 

[grisetti]

[attachment=0:9ax0c0jd]Skimmer rim small.jpg[/attachment:9ax0c0jd][attachment=1:9ax0c0jd]filter element small.jpg[/attachment:9ax0c0jd]

 

[grisetti]

OK, an update. I checked the filter today and the filter was again blue. This time the blue was like slime covering over the element. Any ideas?

Thanks,

Joe

 

[onBalance]

The blue/green on filter is copper. Probably due to low pH in the past and came from copper piping, or from too much usage of copper algaecide.

 

[JohnN]

The Intex SWG has copper bars, which, if you did not unplug them, continuously add copper into your pool.

 

[grisetti]

Thanks, got the pH to normal and have unplugged the copper bars.

 

[Poololigist]

onBalance,
you said above, (The blue/green on filter is copper. Probably due to low pH in the past and came from copper piping) I've read on this site where staining is from high pH.
Can you elaborate on this more please.
Thanks

 

[duraleigh]

OnBalance will explain it better than I but with a too low pH (6.8 or lower) the water is quite aggressive towards metals and dissolves copper out of the pipe and into your pool.

Then, if your pool water pH gets high (say 8.0 or above) the copper precipitates back out of solution into a solid which often takes the form of a stain on your pool surface.

 

[onBalance]

Duraleigh is correct. When the pH goes below 6.8, the water is acidic and that will begin to dissolve copper from the piping. Then there is soluble copper in the pool water. If the acidic water dissolves enough copper (which is also time dependent), then once the pH rises (generally due to some Bicarb or Soda Ash being added), the solubility of the copper lowers and the copper precipitates out and deposits on the pool floor and is caught in pool filters. The reality is that even when the pH rises above 7.0, some copper (because there is a lot of it in solution) will begin to precipitate out. As the pH climbs further to 8.0, even more copper will precipitate out.