Question about the Chemistry of Swimming Pool "Total Alaklinity"

[u/eesemi77]

I don't understand the swimming pool maintenance concept of "Total Alaklinity"

From my High School Chemistry: If I mix Calicum Hydroxide and HydroChloric acid together in a swimming pool then I would expect any excess Hydroxide ions to combine with any available H+ ions to form water. The end result should be CaCl + H2O

I would expect the reaction to happen almost immediately, yet Pool maintenance talks about Total Alaklinity acting as a ph buffer to reduce swings in the water ph over time. To my thinking, the ph of the pool water will be determined by the residual ions either OH- or H+. there's no magical "ph Buffer" that stores this "Alaklinity" without itself changing the ph.

What don't I understand about this reaction?

Edit: Background a recent change in the Pool maintenance company has seen my chemical use more than double (before just HCL) now HCL plus "Alaklinity buffer". Result, I use almost 3 times as much acid as I used to.

Edit2: if anyone else is struggling this is the most useful site I found

https://blog.orendatech.com/total-alkalinity-role-water-chemistry

As others commented it's all about the Carbonic Acid > Bicarbonate + H+ reaction

[u/Combfoot]

Rate of reaction/driving forces of reaction, agitation and convection, alternate reaction, reverse reaction, decomposition.

These plus more I'm not thinking of right now will all lead to pH buffer.

Chemistry is not mathematics, it's a science. 1+1=/=2.

Consider those variables on the system, chatgpt the terms and have a go at discovering why they may cause the observation you have. If you need more guidance drop a DM.

[u/eesemi77 → u/Combfoot]

Thanks, I will give chatgpt a go.

unfortunately searching Google just gave me more references to Pool Maintenance web sites with no discussions of the reaction itself.

As an engineer myself, I hate the idea of something "magical" happening, there's a reason why, and I want to understand it.

[u/Combfoot → u/eesemi77]

Yeah, no magic here. Just things you haven't considered. Heat and mass transfer, chemical thermodynamics, reaction chemistry. They are all real effects. They are what seperates us from the chemists haha

Chatgpt is useful for explaining specific terms and principles, and you can prompt it to give the information from a particular perspective, for a particular audience and provide relevant examples as necessary. AI won't replace us but it is a useful tool to do our jobs better. Like slide rulers to calculators, the tools keep getting better.