Pebblesheen bleach/blotchiness

[Cse001]

Hello TFP members,
I just purchased a home with a pool and am a beginning in the pool game. I've noticed some bleach/blotchiness on a Pebblesheen pool surface. I was wondering if it was just calcium build up or if the surface was potentially bleached? I read about vitamin C and chlorine puck tests to see organic/non-organic. Hopefully can do that when weather gets a bit warmer. From what I can tell, the blotchiness looks likes in on the bottom and sides of pool, in addition to the spa.

Any input would be appreciated! Hopefully my signature will work and has all my pool details.

I tested my water with a Taylor test kit and readings were below if it helps troubleshoot:

PH: 7.8 ( 1 drop of reagent to get down to 7.4)
TA: 110 ppm
FC: 2.0ppm
CC: 0
CH: 175ppm
CYA: 35ppm

16k gallon pool, Pentair DE filter, 1 Pentair WF-28 main pump, 1 Pentair WF-24 waterfall pump, 1 Polaris side cleaner pump, Pebblesheen surface, Pentair heater, air blower, SWG (but currently broken/not in use)

 

[mknauss]

From your pictures it appears to be metal staining. You can do the vitamin C test now.
How is the pool being chlorinated?

 

[Cse001]

Hello Mknauss,
Thanks for your response.

I started with using the trichlor pucks and bought cal hypo shock until I started reading/learning more about liquid chlorine on this site and switched over. From my understanding cal hypo shock may not of been good to use with darker color pebblesheen and may of had some adverse effects/bleaching?

I cant recall if the bleaching/stains were there when I moved in or not (didn't notice them) but starting to get more observant over the first couple months having the pool.

I'll try to get the SWG back working in the near future or may have to get a placement.

 

[Cse001]

I do live in Houston with a city water source (not a well).

 

[mknauss]

If the cal hypo does not fully dissolve it can be an issue.

Any chance copper containing algaecides have been used? Did the pucks that were being used have copper sulfate in them? The word 'Blue' in the name means they have copper in them.

Also low pH. It can destroy the heater and put copper in the water.

 

[mknauss]

Houston water is known to have iron in it. The vitamin C will tell you that quickly.

 

[Cse001]

The pucks that were used (Bioguard SilkGuard) contain the below ingredients, I didnt see "Blue" specifically but do see the copper sulfate below?

Trichloro-s-triazinetrione: 91.57%, Copper Sulfate pentahydrate (metallic copper equivalent 0.25%): 0.99% Other Ingredients: 7.44%, Available Chlorine: 84.%

Historically from what I've noticed, the pH always seems to be on the high side/rising and I've been using Muriatic Acid (maybe 2 quarts per week on average) every week to keep it down - its a constant battle.

The previous owner did leave some bottles of various Phosguard/algaecides, maybe I can review them and see what the regiment was... however the house was vacant for about a year so a pool company was taking care of the maintenance.

 

[mknauss]

however the house was vacant for about a year so a pool company was taking care of the maintenance.

That is a sure sign of copper algaecide use.

Test the stain with Vitamin C. If no change or it gets darker, then it is copper.