Why is sulfuric acid not so good for plaster pools?

[smallpooldad]

Just this quick question.

The reason for asking is that I have in the past dropped muriatic acid on my concrete and it leaves nasty little holes in it and scares the top. I have dropped battery acid, equals 35% Sulfuric acid and all it did was clean it up without leaving holes or scars.

So why is it not recommended for plaster. To my mind it is better because of the following reasons;

1) It does not scar.

2) It does not affect the alkalinity as much (one does not have to add alkalinity increaser as often).

3) If I get it on my hand it does not sting as fast.

4) It precipitates iron and copper not putting it into solution which is harder to remove.

5) It does not have a stinging inhalation fog to avoid.

6) I read somewhere once that it leaves a lot of TDS in the pool. This is not my experience.

7) It costs $16 for 5 gallons at my local Napa store (although they look at me very strangely) versus $9.50 for one gallon of muriatic acid. These are Hawaii prices where nearly everything is at least 15-25% more than the mainland.

Look forward to all of your comments.

[mwsmith2]

Well, it will affect alkalinity equaly the same if you are reducing down to the same pH level. However, I'm not sure if a carbonate buffering system works with sulfuric acid. Since it isn't changing, you essentially have an unbuffered pool.

Sulfuric acid is H2SO4. Hydrochloric is HCl. All the components of hydrochloric will offgas, leaving nothing behind. Sulfuric acid will continue to build up sulfur in your pool, eventually creating a health hazard.

This is a really Bad Idea.

Michael

[smallpooldad]

Thank you for your reply.

I only used it once to remove iron through sedimentation as ascorbic puts it into solution and falls out again even with metal out. Seems to have worked.

I will use Muriatic on an ongoing basis for normal treatments.

Two questions: 1) What is carbonate buffering? 2) What type of sulfur will come out of solution and can it be filtered?

Once again thanks for all the help.

I will use it to clean the rust stains off my concrete.