Risks with high alkalinity?

[chem geek]

Jennifer,

You did great. Thanks for the info. You may have hit on a procedure that may work well for people with high alkalinity tap water. We'll see how Rangeball does with it!

Richard

[Rangeball]

Jennifer,

You did great. Thanks for the info. You may have hit on a procedure that may work well for people with high alkalinity tap water. We'll see how Rangeball does with it!

Richard

Just found out last night that we're having another kid fest Thursday night. Aeration x 100

I plan to lower my PH to around 7 pre party and let them have at it. I'll test the next morning to see where things leveled out.

[Tredge]

Just found out last night that we're having another kid fest Thursday night. Aeration x 100

I plan to lower my PH to around 7 pre party and let them have at it. I'll test the next morning to see where things leveled out.

Aeration X100 means a much faster rise in PH. I'd consider adding Acid mid-party to maintain the PH at ~7. Put those kids to work!

[Rangeball]

Aeration X100 means a much faster rise in PH. I'd consider adding Acid mid-party to maintain the PH at ~7. Put those kids to work!

From Jen's post above-

What I have found is that vigorously aerating it seems I evaporate more water with out rising the ph faster.

I'm confused. Which one is right?

[chem geek]

I'm confused. Which one is right?

From a technical point of view, more aeration means more outgassing of CO2 which means more of a rise in pH. However, there may be a point of diminishing returns and that may be what Jen saw -- that vigourous aeration caused more evaporation but not a noticeable increase in pH. She wasn't saying that aeration did not cause a rise in pH, but rather that extra vigorous aeration didn't seem to make the pH rise much faster but did increase the evaporation rate quite a bit. She found that a good tradeoff was made by doing some aeration that was less vigorous.

The processes that determine the rate of outgassing and evaporation are very complicated. Both depend on the surface area of the air-to-water boundary (including that boundary in droplets) but the specifics of the rates may be quite different. Nevertheless, if certain droplets were to completely evaporate, then you would lose both the water and the carbonate in that water into the air leaving only some salt (like sea spray) to eventually fall back to the ground or get whisked away by wind.

So I don't have an explanation for Jen's observation of an increase in evaporation without an increase in pH. I could imagine that there is a small increase in pH but that the rate of evaporation increases much more so that it appears that it dominates what's going on. The evaporation process may have a non-linear and more rapid runaway effect compared to the CO2 outgassing, but that's just a wild guess on my part.

Richard

[Rangeball]

Ok.

I plan to add the acid and drop the PH as low as possible tomorrow morning so the pool will be ready for them swimming 10 hours later. However, they are now calling for scattered thunderstorms, but I guess I'll still be ok if it rains and we call the kids off because I've noticed rain is one heck of an aerator also

[KurtV]

Ok.

I plan to add the acid and drop the PH as low as possible tomorrow morning so the pool will be ready for them swimming 10 hours later. However, they are now calling for scattered thunderstorms, but I guess I'll still be ok if it rains and we call the kids off because I've noticed rain is one heck of an aerator also

And beyond that, the pH of normal rain is something like 4.5 to 5.5 (and even lower for "acid rain").