Pool pebble surface blotchy spots from high chlorine? Builder says my fault-need help

[oldguy70]

I actually think it's better to pour all of the acid slowly in front of one return than to broadcast it like this. When you pour directly into the return stream, the acid is immediately pushed away from the walls and diluted quickly into the center of the pool. When you pour away from a return, even with the pump on the acid spends more time concentrated near the wall/floor until the natural circulation dilutes it.

Plus, staying in one place means less risk of slipping/spilling (I always seem to be adding acid and chlorine when it's dark and the Irish Wolfhound is "helping", so walking along the pool edge with an open cup/bottle of acid makes me shudder)

The Caretaker system mixes the acid quickly throughout the pool...mixing & diluting is not the problem

 

[oldguy70]

There is much science on this forum to backup the FC/CYA relationship but as I mentioned before, it will be falling on deaf ears. The pool industry does not recognize this relationship and will likely be (and were) appalled when they saw a FC level of 15.

Chem Geek (Richard Faulk) is the resident expert on the FC/CYA relationship and is responsible for much of the research and understanding on the topic (the main premise behind this site). He has tirelessly devoted much time to educate the pool industry on this simple bit of knowledge but even he had limited success. He has not been around in a good amount of time, which is unfortunate since he could easily show the research to back my previous statements.

OnBalance is the plaster expert on this site. Perhaps he could provide some insight on what he feels may have happened but I still don't think that will help your cause.

There are several more experts on this site but keep in mind that this is a forum for homeowners to manage their own pools. Nothing more than sympathy can be offered to you since the plaster company has already showed you their hand and since the water was maintained outside of their recommendations, I don't know that you have a leg to stand on.

Thanks for all your comments and recommendations, its not that I didn't follow the builders recommendations, as he had no recommendations for chemicals and it was up to me, however, I am not looking for an out, just what caused the problem so it may be solved. Here is an update.

The builder is contacting (Copied from text message received from my builder) .....Greg Garrett has more than 40 years’ experience in the swimming pool industry principally in the construction trades involving concrete, plaster and other cementitious materials. Beginning in 1983, Greg focused on pool interior finishes and pool deck phenomenon. He has conducted research on etching deterioration, calcium nodules, discoloration and methods to improve the long-term resistance to chemical deterioration of interior finishes. In concrete, he has researched ASR (Alkali-Silica Reactivity) and sulfate type attacks and has ongoing research in modified deck toppings and modified concrete for the swimming pool industry and other industries. Greg is the president and owner of Applied Materials Technologies (AMT). Greg holds a KA-05 dual residential and commercial swimming pool contractors’ license in the state of Arizona. Greg serves on the Board of Directors of The National Plasterers Council and also serves as Director of Technical Service.

I would guess such a person would be in a position of be able to determine what caused this issue, I am not sure when he will be looking at my pool, I will update anything new. Also if anyone else can shed any light on this...thanks