Adding calcium

[Ngosch]

Hello,

We have a brand new fiberglass pool with SWG that I am trying to manage myself. I need to add around 50 pounds of calcium. The pool store told me only 14 pounds at a time and then to wait 4 hours in between. Is this necessary? Thanks all!

 

[Texas Splash]

Welcome to TFP! Can you clarify why exactly you are adding calcium to your FG pool? Do you have a waterline tile? Also, your signature is blank and doesn't show any details about your pool or equipment. Can you confirm the size (gallons) of your pool?

 

[Ngosch]

Thank you for your reply. I’ll work on getting my signature updated. It’s 13,901 gallons, no waterline tile. I took some water to the pool store and that’s what they recommended. I also inputted it into the pool math app and it told me the same thing only even more calcium than the pool store recommended. needless to say, I am confused.

 

[Texas Splash]

needless to say, I am confused.

Ha ha. Let me try to help. Our FG pools (much like vinyl) technically don't need calcium like a plaster pool. TFP recommends a minimum CH of 250 basically for general water balance and protection from unusual staining. You could actually get-by with a CH even lower than 250 if you wanted and probably be just fine.

 

[Texas Splash]

If you only wanted to increase the CH 150, it would require about 19 lbs of calcium. To take it to 200, it would be about 26 lbs, and finally a CH of 250 would need 32 lbs. If you have really hard local water, I would add less calcium, but if you have soft water or see lots of rain and water exchange each season, maybe opt for the larger CH level.

Less calcium means less potential for scale which is important for your SWG cell as well.

 

[Ngosch]

Ok, that makes sense. Thank you!

 

[Texas Splash]

You're welcome. Oh, one final thought since you will be updating your signature later. If you have a heater, check your owner's manual as some heater manufactures list a minimum CH level. If you don't have a heater, no worries.

From Recommended Pool Chemicals - Trouble Free Pool

CH – Calcium Hardness

Calcium hardness can be raised with calcium chloride or calcium chloride dihydrate. They are available in some areas as Peladow, Dowflake, Tetra Flake, or Tetra 94, often sold as a deicer by hardware stores, and some big box stores, in colder climates. Pool stores will carry either calcium chloride or calcium chloride dihydrate under a variety of names, including Hardness Plus, Balance Pak 300, Calcium Hardness Increaser, etc. Calcium products should be spread across the surface of the deep end of the pool.

Mixing calcium in water will generate a lot of heat. Do not mix calcium in a bucket of water before you add it to the pool.

 

[Ngosch]

Oh, good to know! I do have a heater. It’s a Pentair Mastertemp 200 and it’s running quite a bit right now. I’ll check that out. Thanks!

 

[Texas Splash]

It’s a Pentair Mastertemp 200

From the Pentair manual ...

Calcium Hardness, ppm, as CaCO3: (Min) - 150 (Ideal) - 200-400 (Max) - 500-1,000

 

[Ngosch]

Thank you so much!