Some type of stain?

[lone_starr]

A few months ago we began noticing our plaster discolor in the deep end of the pool. It spread in the deep end, but stopped. I've tried all sorts of algae treatments and nothing seems to help. Our pool's chemistry is maintained at normal levels and I've run out of options, so any help would be appreciated. Please see the attached pictures for details.

Thanks in advance.

 

[jblizzle]

Welcome to TFP!!!

How does it feel?
As a guess ... calcium scaling perhaps with some embedded metal staining?

Have you ever added calcium to the pool? Or dumping cal-hypo chlorine powder into the pool and let it sit on the bottom?
Ever added algaecides or trichlor tablets with copper in them?

What test kit do you use?
What are your test results? ... statements like "normal levels" do not mean anything to us.

 

[Mendy48]

Welcome!!!

How are you today!!!

One of the first thing I'm going to ask is if you have your own test kit. Getting a better understanding of your pool chemistry as it stands today will help diagnose whats going on. In other words, we would need to know your FC, CC, pH, TA, CH and CYA. If you don't have a test kit, we recommend the TF100 from TFTestKits.net or the Taylor K-2006C.

You stated that your pool chemistry is maintained at normal levels. How, exactly, are you maintaining your normal levels of the above chemistry. We don't relay on pool store results, so if you don't have a test kit, please get one asap.

Here are some links that will help you!!!
Pool School - ABCs of Pool Water Chemistry
Pool School - How to Chlorinate Your Pool
Pool School - Chlorine / CYA Chart
Pool School - Recommended Pool Chemicals
Pool School - SLAM - Shock Level And Maintain

 

[lone_starr]

Thanks for the welcome

We have maintained the pool since building it in 2011 and have never added calcium directly to the pool. This summer we used Clorox Xtra Blue Shock (Amazon.com : Clorox XtraBlue Pool Shock 24-pack : Garden Outdoor) on a consistent basis - approx 1lb bag every 1-2 weeks. I don't think it ever stat on the bottom...

We use a HDX pool test kit from HomeDeport for chlorine and pH measurement as well as take samples to Leslie's once a month. Apologies for the generic test information previously but chlorine stays between 1-3 during the summer (temps in Austin are hot during the summer and pool maxes out around 90F) and pH has constantly been in the mid-7s. When we've taken samples to Leslie's the only request has been to add more chlorine when the level is low and the water temperature is high.

Hope that helps.

 

[jblizzle]

Clorox Xtra blue includes copper so there's your source. Also and FC of 1 to 3 PPM is very likely not nearly high enough to avoid algae as it is really a function of your cya. And that extra blue shock would also be raising your cya.

You really need to get one of the recommended test kits if you want to take control of your pool. And also very likely need to switch to liquid chlorine.

 

[kimkats]

This summer we used Clorox Xtra Blue Shock (Amazon.com : Clorox XtraBlue Pool Shock 24-pack : Garden Outdoor) on a consistent basis - approx 1lb bag every 1-2 weeks. I don't think it ever stat on the bottom...
.

I think we found it. ^^^^^^^^^^^^^^ that stuff has copper in it Copper, over time, can cause stains. Here is one thing you can do to see if it is copper. Try holding a vitamin c tablet on the stain. Make sure it is the white one. Let us know what you see.

 

[lone_starr]

Appreciate the info and recommendation on the test kits. Do you have any additional recommendations for liquid chlorine and should i apply something like Scalefree Pool Scale Metal Protection ─ Pool Supplies ─ In the Swim to take care of the copper?

- - - Updated - - -

@kimkats will definitely use that advice to test - thanks!

 

[jblizzle]

Sequestrants like that are just good to keep the metal in the water to prevent staining. They will not remove the stain.

 

[wjr75]

That's what our old plaster looked like when we bought our house and one of the reasons we did a replaster with Pebble Tech pebble sheen. We had it drained and power washed every year on opening but the stains still would come back by the end of the summer. The previous owners used pucks and a Nature 2 sanitizer which I have removed since moving in. Not sure of the cause but it sure bothered me.

 

[jblizzle]

Nature 2 also adds copper.

 

[kimkats]

If it is possible the best thing would be be to replace as much of the water as you can. Like said above the metal will stay in the water so if you replace the water you will get rid of the bad stuff.

I am very interested to see what the vit C test does.

Kim