problem - is this etching or scaling

[carlos31]

This problem seemed to sneak up on me quickly. Its 6 month old grey plaster. I have let the PH get high a few times but I can't believe enough times to cause this level of damage.

Here are links to the pictures.

http://i371.photobucket.com/albums/oo152/jollyroger31/2009_02_02_misc019.jpg

http://i371.photobucket.com/albums/oo152/jollyroger31/2009_02_02_misc021.jpg

http://i371.photobucket.com/albums/oo152/jollyroger31/2009_02_02_misc022.jpg

It looks like pitting and erosion on the horizontal surfaces, but the walls are largely unaffected. The wall return in the picture looks like scaling, but I thought these two effects were opposite sides of the problem spectrum.

I don't care about the speckled white look in the grey plaster; I actually kind of like it since it hides the mottling and streaks. However, I am concerned about the surface being rougher than unaffected plaster and the life span of the plaster.

What problem do I have and is there any way to stop it or reverse it? Where do I go from here?

Current readings = PH=7.7, TA=100, CH=350, FC=1, CC=0, CYA=30, water temp=55.

Thanks.

 

[spishex]

It looks like pitting and erosion on the horizontal surfaces, but the walls are largely unaffected. The wall return in the picture looks like scaling, but I thought these two effects were opposite sides of the problem spectrum.

What kind of granular chemicals have you added?

 

[carlos31]

I don't use anything that is granular. Liquid Bleach with Liquidator. CYA was liquid form. Only sand or dirt blown into the pool would be granular and I don't fertilize or anything similar.

 

[spishex]

Well there goes that. :lol:

Does it have any sort of texture to it?

The buildup around the return looks like a calcium nodule which is usually benign and can be removed with a drywall sander or similar abrasive. Here's an article on them.

 

[carlos31]

yes, its somewhat rough not smooth like the walls which are mostly undamaged - it looks like small pits/holes in the plaster

Would high PH cause this? I thought only low PH caused this effect.

thanks,