Plaster in ground pool, brought my CH up from 140 to 270...am I good?

[CajunGuy]

I was a bit worried about my CH being too low for my plaster in ground pool, so I ended up adding 16 pounds of Calcium Chloride and it brought my CH up to 270 now. Each 4 pounds brought it up about 30ppm. Should I get another 4 pounds to bring it up to 300-310 or is 270 sufficient now? Thanks!

P.S. What exactly does "calcium leaching" look like in the plaster? Is it just white spots or does the plaster actually degrade? Googled it, but got a bunch of different pics, so I'm not sure now.

 

[Texas Splash]

The TFP recommended CH range for a plaster-SWG pool is 350-450. Yes, I would increase it, especially if you are lucky enough to have very soft fill water. Surfaces that start to become damaged from a lack of calcium (example leaching) can exhibit various signs of damage to include abnormal streaking, blistering, thinning appearance, etc. The calcium from within the pool's plaster is literally being stripped-away into the water. For leaching specifically, think of it as a chemical or liquid that is "seeping through" another substance as illustrated HERE.

 

[CajunGuy]

The TFP recommended CH range for a plaster-SWG pool is 350-450. Yes, I would increase it, especially if you are lucky enough to have very soft fill water. Surfaces that start to become damaged from a lack of calcium (example leaching) can exhibit various signs of damage to include abnormal streaking, blistering, thinning appearance, etc. The calcium from within the pool's plaster is literally being stripped-away into the water. For leaching specifically, think of it as a chemical or liquid that is "seeping through" another substance as illustrated HERE.

I'm going to bump it up some more. What's the reasoning behind why plaster pools with SWGs need a range of 350-450 as opposed to plaster pools with bleach only needing 250-350?

 

[Texas Splash]

Much of that is based on research from experts in the field like "Chem Geek" who have offered descriptions such as this:

The TDS, so salt level, also affects CSI where salt pools at 3000 ppm have around 0.2 units lower CSI all else equal. Our current Recommended Levels are still inconsistent and low in CSI for SWG pools where they should have an even higher CH for plaster because 1) the higher salt level has the CSI be 0.2 units lower and 2) the higher CYA recommendation has the CSI be 0.1 unit lower and 3) the lower TA has the CSI be 0.07 units lower while the higher pH target only has the CSI be 0.05 units higher.

That was from THIS THREAD.

Basically it's all tied-into the pool's CSI level.

 

[RobbieH]

Ah, glad I read this thread. This is new info to me (I was gone for a long time - dang work gets in the way). I need to raise my CH!

I have noticed my CSI will sometimes go out of range, but for the most part I've ignored it.

 

[RobbieH]

I need 50-60 lbs of calcium chloride. Does this look like the right thing? This is about 1/4 the cost at Leslies.

Snow Joe 50 lb. Re-Sealable Bag Calcium Chloride Crystals Ice Melter-MELT50CC - The Home Depot

Or this, which is flakes...
Vaporizer 50 lb. Calcium Flake Ice Melt Bag-VP-CF50BG - The Home Depot

This one is a lot more, but they mention using it in pools
Amazon.com : North American Salt 50850 Extreme 7300 Calcium Chloride Ice Melter, 50-Pound : Snow And Ice Melting Products : Patio, Lawn Garden

Or any of them?