Questiions regarding adding large amounts of calcium to pool

al27

Well-known member
Sep 11, 2017
66
Franklin, TN
I need to add over 20 pounds of calcium to my pool. I could use some advice on the best way to get all of this calcium into my pool without causing other problems. Water is cold (60s) so I wasn't sure if I need to dissolve it in a bucket and dump it in the pool or if it would dissolve well enough in cold water to just broadcast it in the deep end and brush afterwards like is recommended on here. I assume that I shouldn't add all 20 pounds at once so I'd like some advice on how much to add at a time and how long to run the pump afterwards before adding chlorine and turning the pump off. I can add it over several days if needed. Last time I added calcium, I noticed a stain that I haven't been able to remove so I'm a bit nervous about adding so much of it to my pool.
 

ajw22

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TFP Guide
Jul 21, 2013
10,785
Northern NJ
Re: Questiions regarding adding large amounts of calcium to pool

Why?

What is your CH? What is your CSI? Post your full test results.

A fiberglass pool does not need a lot of CH.
 

al27

Well-known member
Sep 11, 2017
66
Franklin, TN
Re: Questiions regarding adding large amounts of calcium to pool

Calcium was only 120 when I checked it a few days ago and CSI was -0.44. There is a white chalky substance covering the walls and I have water line tile so I'd like to raise the calcium level before closing. I called the manufacturer of my fiberglass pool and they said the chalking was probably caused by low calcium and high PH. The manufacturer recommended that I raise the CH to 300-350. I just need to know how to add all of this calcium without causing other problems since the water is cold.
 

duraleigh

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Apr 1, 2007
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Sebring, Florida
Re: Questiions regarding adding large amounts of calcium to pool

To answer your question, I would suggest putting CH in your pool in about 5 lb increments.......that should minimize any side effects.

Now, I know you didn't ask but I would not add ANY if it was my pool.......at least, not before I determined some other things first.

Whether or not FBG pools need any CH is debatable. The grout in the tile could POSSIBLY benefit from adding CH but maybe only up to 200 if it were me.

1. What is your pH?

2. What is the CH of your fill water?

3. I have never heard of chalking as a result of LOW calcium......high, maybe, but not low.

4. I would try to determine another cause for the chalkiness......I don't think it is low Calcium.

5. Where is Franklin with a water temp of 60 already?
 

al27

Well-known member
Sep 11, 2017
66
Franklin, TN
Re: Questiions regarding adding large amounts of calcium to pool

To answer your question, I would suggest putting CH in your pool in about 5 lb increments.......that should minimize any side effects.

Now, I know you didn't ask but I would not add ANY if it was my pool.......at least, not before I determined some other things first.

Whether or not FBG pools need any CH is debatable. The grout in the tile could POSSIBLY benefit from adding CH but maybe only up to 200 if it were me.

1. What is your pH?

2. What is the CH of your fill water?

3. I have never heard of chalking as a result of LOW calcium......high, maybe, but not low.

4. I would try to determine another cause for the chalkiness......I don't think it is low Calcium.

5. Where is Franklin with a water temp of 60 already?
Thank you for the advice. PH has been 7.6-8.0 all summer and I haven't been diligent enough about lowering it because we haven't been swimming in the pool much. Our fill water has low calcium and we have been adding a lot of water this summer because we had a leak that was hard to find. The chalkiness started when we started adding water often to our pool so I'm hoping that it will go away once we increase the CH level. Since we will be adding the calcium to colder water, should we dissolve it in a bucket and pour it around the pool or will it dissolve well enough in colder water to broadcast it around the deep end and brush afterwards? I've never added calcium to colder water before so I wasn't sure if I needed to take any special precautions when putting it into the pool.
 

al27

Well-known member
Sep 11, 2017
66
Franklin, TN
Re: Questiions regarding adding large amounts of calcium to pool

I need to add calcium to my pool. I read that it tends to harden quickly when added to cold water which concerns me since the water temperature is around 65 degrees right now. If I broadcast it in the deep end like is recommended on here, I'm concerned it will quickly harden and be difficult to remove since the water is rather cold. Would it be safer for the surface of my pool if I dissolve some in a bucket of pool water and pour it around the deep end? I've read that it gets hot when added to a bucket of water but I'd be willing to try if it would decrease the chance that some calcium hardens on the bottom of the pool. If I only added a few pounds at a time to a large bucket and stirred it with a wooden stick until it dissolves, would it get hot enough to burn me or damage the bucket? After I add it to the pool, how long do I need to run the pump afterwards and how long do I need to wait before adding chlorine to the pool?