Why is it called Calcium Hardness?

[Household6]

Those with plaster pools need calcium hardness in the water, right?

This is so the plaster does not get too brittle/hard and start to crack and chip, right?

So why is it called calcium HARDNESS?

I mean, the idea is to put something in to prevent the walls from getting TOO HARD and brittle!

BTW, regarding the Clorox Calcium Hardness Increaser, that falls under Calcium Chloride (not Calcium Chloride Dihydrate), right?

**Mad props to @briwill for the 6 jugs of increaser I picked up from him today (as well as the 4 jugs of pH + and - for my neighbor). Considering I can’t find any de-icer, he took some of the sting out of needing 73 lbs of the stuff to bring my CH from 50 to 270! That’s what I call “good people!”**

 

[pooldv]

Calcium chloride dihydrite is fine. More here, Pool School - Recommended Pool Chemicals

You might be able to order deicer at Lowe's and have it delivered to the store for free and then you can pick it up at the store.

The need for a proper CH level in a plaster pool is to prevent etching of the plaster surface. Etching is caused by calcium dissolving from the plaster into the water leaving pits in the surface. More here, Pool School - Calcium Scaling

 

[briwill]

Those with plaster pools need calcium hardness in the water, right?

This is so the plaster does not get too brittle/hard and start to crack and chip, right?

So why is it called calcium HARDNESS?

I mean, the idea is to put something in to prevent the walls from getting TOO HARD and brittle!

BTW, regarding the Clorox Calcium Hardness Increaser, that falls under Calcium Chloride (not Calcium Chloride Dihydrate), right?

**Mad props to @briwill for the 6 jugs of increaser I picked up from him today (as well as the 4 jugs of pH + and - for my neighbor). Considering I can’t find any de-icer, he took some of the sting out of needing 73 lbs of the stuff to bring my CH from 50 to 270! That’s what I call “good people!”**

I'm glad i could help, this definitely seems like a good community of people that help each other out!

 

[pooldv]

Yay! Good stuff!

 

[Household6]

Calcium chloride dihydrite is fine. More here, Pool School - Recommended Pool Chemicals

You might be able to order deicer at Lowe's and have it delivered to the store for free and then you can pick it up at the store.

The need for a proper CH level in a plaster pool is to prevent etching of the plaster surface. Etching is caused by calcium dissolving from the plaster into the water leaving pits in the surface. More here, Pool School - Calcium Scaling

Etching, pitting, cracking . . . you say tomato, I say red round and good on bread with mayo.

So they call it HARDNESS INCREASER because you’re trying to make the surface harder so it doesn’t compact and push the calcium out?

I take it de-icer is calcium chloride and the stuff specifically labeled for pools (like the Clorox brand) are the ones with dihydrite?

 

[Rocket J Squirrel]

It’s not a pool-specific term. Have you never heard of “hard water” and “soft water”? It’s all about the level of calcium in the water.