I'm generally successful at keeping my pool's pH in the 7.2-7.4 range
without too much hassle. However, every time it rains, it takes what
I consider to be a dramatic drop. We got about .1" of rain yesterday
and, as expected, the pH dropped to 6.8. The pool is a 24x48 round
above ground, 13,000 gallons or so. If my math is correct, .1" is
approximately .2% of the total volume. With that much of an effect
on the pH of the pool water, I would expect to see my concrete patio
etched clean! I'm able to bring it back up to 7.2-7.4 with about a
pound of soda ash, so it's not a major problem. I'm just confused at
how so little rain can have so big an effect.

What am I missing?

Mike Hartigan wrote:
I'm generally successful at keeping my pool's pH in the 7.2-7.4 range
without too much hassle. However, every time it rains, it takes what
I consider to be a dramatic drop. We got about .1" of rain yesterday
and, as expected, the pH dropped to 6.8. The pool is a 24x48 round
above ground, 13,000 gallons or so. If my math is correct, .1" is
approximately .2% of the total volume. With that much of an effect
on the pH of the pool water, I would expect to see my concrete patio
etched clean! I'm able to bring it back up to 7.2-7.4 with about a
pound of soda ash, so it's not a major problem. I'm just confused at
how so little rain can have so big an effect.

What am I missing?

Not what you are missing, but maybe what you are getting - Acid Rain the
most acidic rain falling in the US has a pH of about 4.3.

--
Joseph Meehan

Dia duit

Rain - contains lots of things and in turn that changes
the pool's ph. You won't see etching etc. from those
strengths unless a very long period of time is studied,
but obviously it's what's in the rain that causes it.
Collect some rain and check its ph; you'll see what
I'm talking about. Don't overthink it; just use common
sense and logic.




"Mike Hartigan" wrote in
message
.net...
I'm generally successful at keeping my pool's pH in
the 7.2-7.4 range
without too much hassle. However, every time it
rains, it takes what
I consider to be a dramatic drop. We got about .1"
of rain yesterday
and, as expected, the pH dropped to 6.8. The pool is
a 24x48 round
above ground, 13,000 gallons or so. If my math is
correct, .1" is
approximately .2% of the total volume. With that
much of an effect
on the pH of the pool water, I would expect to see my
concrete patio
etched clean! I'm able to bring it back up to
7.2-7.4 with about a
pound of soda ash, so it's not a major problem. I'm
just confused at
how so little rain can have so big an effect.

What am I missing?

"Mike Hartigan" wrote in message
.net...
I'm generally successful at keeping my pool's pH in the 7.2-7.4 range
without too much hassle. However, every time it rains, it takes what
I consider to be a dramatic drop. We got about .1" of rain yesterday
and, as expected, the pH dropped to 6.8. The pool is a 24x48 round
above ground, 13,000 gallons or so. If my math is correct, .1" is
approximately .2% of the total volume. With that much of an effect
on the pH of the pool water, I would expect to see my concrete patio
etched clean! I'm able to bring it back up to 7.2-7.4 with about a
pound of soda ash, so it's not a major problem. I'm just confused at
how so little rain can have so big an effect.

What am I missing?

Boost your alkalinity levels. It acts as a buffer against large ph swings.
Most strip tests kits have it listed.

Mike Hartigan writes:

What am I missing?

Maybe your pH tests or procedures are no good. (What is your basis for
trusting them? False results are easier to get than true, and it takes
knowledge and diligence to keep them in line. If you've never calibrated
your tests, then they can't be trusted.) Adding about 1 part in 1000 of
rainwater does not seem like it could have such an effect.

The first step is to confirm the readings.

"Mike Hartigan" wrote in message
.net...
I'm generally successful at keeping my pool's pH in the 7.2-7.4 range
without too much hassle. However, every time it rains, it takes what
I consider to be a dramatic drop. We got about .1" of rain yesterday
and, as expected, the pH dropped to 6.8. The pool is a 24x48 round
above ground, 13,000 gallons or so. If my math is correct, .1" is
approximately .2% of the total volume. With that much of an effect
on the pH of the pool water, I would expect to see my concrete patio
etched clean! I'm able to bring it back up to 7.2-7.4 with about a
pound of soda ash, so it's not a major problem. I'm just confused at
how so little rain can have so big an effect.

What am I missing?

Whats your total alkalinity number? Alkalinity is your buffer (kinda like
buffered aspirin). It is there to prevent wild pH swings. If its within
nominal than I would just say you have some very serious acid rain and alot
things around you should be dissolving by now.

In article , "Joseph Meehan" wrote:
Mike Hartigan wrote:
I'm generally successful at keeping my pool's pH in the 7.2-7.4 range
without too much hassle. However, every time it rains, it takes what
I consider to be a dramatic drop. We got about .1" of rain yesterday
and, as expected, the pH dropped to 6.8. The pool is a 24x48 round
above ground, 13,000 gallons or so. If my math is correct, .1" is
approximately .2% of the total volume. With that much of an effect
on the pH of the pool water, I would expect to see my concrete patio
etched clean! I'm able to bring it back up to 7.2-7.4 with about a
pound of soda ash, so it's not a major problem. I'm just confused at
how so little rain can have so big an effect.

What am I missing?

Not what you are missing, but maybe what you are getting - Acid Rain the
most acidic rain falling in the US has a pH of about 4.3.

Assuming his figures are correct, the pH of the rain necessary to produce the
observed change in the pool calculates to.... four point three.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.