Not sure what to do - sending up a flare!

[stappertx]

I've been using the TFP method for three years with no hiccups. This summer, I went on an unexpected 1 week trip when the temps in Dallas were over the 100 degree mark. When I returned, my FC levels were at zero. I started feeding the pool liquid Clorox, which it consumed at an alarming rate. All other markers were at pool school levels (CYA at 50) other than the chlorine and the water was crystal clear. I immediately went into slam mode and kept the FC levels over 25 ppm for two weeks. At that point, it was still consuming over 6 gallons of 6% bleach per day, so I drained the pool before leaving for a 10 day vacation.
As I drained the pool, I noticed that the surface was white rather than the Aqua Blue pebble sheen color we had purchased 3 years ago. When I returned from vacation, I cleaned the grids in the filter and started to fill the pool back up. I decided to remove some efflorescence around the hot tub and poured some acid on the build-up. When the acid ran down the wall, the streaks turned from white back to the Aqua Blue color we had three years ago. I'll attach a picture of that.
My question for the TFP/PebbleSheen gurus is ... Do I have a service chlorine/acid wash my pool before filling it, or do I fill it and then drop the PH down to a level where it will remove all the white residue from the surface? I'm not sure if the white surface is related to the crazy amount of chlorine I was dropping in, or if it is something that will go away with a low PH level.

Thanks!
Steve

 

[Divin Dave]

I really cannot tell you what the white stuff may be. The only thing that comes to mind is calium scaling, but it seems the entire surface is that way, which is usually not the case with scaling.
Hopefully someone else will come along with more experience than I have with plaster surfaces.

I can tell you though, that the white stuff is not eating the chlorine. Chlorine is only consumbed by either UV from the sun, or by organics.

 

[YippeeSkippy]

Can you provide a full set of test results?

How were you planning on chlorinating your pool while gone on these vacations?

 

[stappertx]

On the first trip, I just left without having a good plan to continue chlorinating. That was the start of my trouble. Before the second trip, I drained the pool after two weeks of feeding it 6 to 8 gallons of bleach per day.
Beyond the chlorine, here were my last test results before draining the pool:
- PH 7.6
- TA 110
- CH 250
- CYA 50
no CC

Thanks

 

[YippeeSkippy]

huh. Your CH wasn't ridiculously high or anything... I dunno what to suggest?

If you rub a small area with a very dilute MA solution, the blue pops up again??

 

[duraleigh]

Do I have a service chlorine/acid wash my pool before filling it, or do I fill it and then drop the PH down to a level where it will remove all the white residue from the surface?

I would do both

Assuming acid will continue to remove the white coating, about the only thing it can be is calcium scale and an acid wash should remove most of it.

Calcium scale can occur at a low CH level if you have chronic high pH. Conversely, keep your pH chronically low will begin to slowly remove it. I think if it were my pool, I would acid wash it and then run the pH at 7.0 or 6.8 if you can mange that very carefully. Do not go lower than 6.8 so you will have to be very meticulous about your testing methods.

 

[stappertx]

Thanks for the help! This morning I tested various acid dilutions to see what would happen - each level poured onto a different spot. 1/8 acid didn't do much. Every step up from that (1/4, 1/3, 1/2) acid to water ratio would bring out more of the blue we saw when we had the Pebble Sheen installed.
If this means that an acid wash is in order, is that something most of you would attempt yourselves or leave to a professional?

 

[duraleigh]

google "no drain acid wash" if you are a good DIY sort. Pay attention and do it right and you will not have to hire someone.

 

[stappertx]

Thanks Duraleigh. After doing a lot of reading on that, I think I'll go with the no-drain version of the acid wash to be kinder to my pool surface.
Two questions:
- My pool is drained now. When I fill it, do I balance to normal swimming chemistry first and then drop the TA/PH, or do I just fill it and try to get to low PH right away?
- Should the pump be on during the no-drain acid wash process? I saw conflicting info on that one.

Thanks!