SWG - muriatic acid vs dry acid

[choitink]

Hole to be dug and pool in the ground by Friday. Likely full of water by this time next week.
Been reading a lot about pool water care thanks to TFP.

Question:
Only pool store in town is suggesting that dry acid would not be a problem with a SWG, and they have never heard this could be a problem. I was planning on using muriatic acid, but seems like it would be nicer to handle the dry acid. What is the issue with dry acid and SWG?

Thank you

 

[duraleigh]

There is a residual left behind with dry acid (for the life of me, I can't remember what it is) and there is literally no side effects whatsoever with muriatic.

Once you learn a procedure for handling it, muriatic is actually quite easy to handle. In 7-8 years, I have yet to be burned or spilled any on my clothes. Twice I can remember get downwind and getting a noseful of the fumes.....I soon learned not to do that anymore.

 

[Melt In The Sun]

Sulfates are the issue, according to the manufacturers. They state that high sulfate levels, caused by adding dry acid over time, can damage the plates in an SWCG cell. As an aside, sulfate-laden water can be really destructive to concrete, mortar, etc. Even without an SWCG, I wouldn't use it in my pool. Plus, it's generally more expensive.

 

[choitink]

Thank you. This website is great.

 

[chem geek]

Sulfates are the issue, according to the manufacturers. They state that high sulfate levels, caused by adding dry acid over time, can damage the plates in an SWCG cell. As an aside, sulfate-laden water can be really destructive to concrete, mortar, etc. Even without an SWCG, I wouldn't use it in my pool. Plus, it's generally more expensive.

We knew about the issues with sulfates on plaster and hardscape stone as described in Sulfates why so bad? and Sulfates - what's the problem?. However, I couldn't find anything specific on what happens with sulfates and an SWCG. Did the manufacturer say that there was specific precipitation of some chemical (and if so, what it was) or whether there was some more direct attack on the SWCG coatings by sulfate?