Adding calcium chloride by volume means use a measuring cup, right?

[Skenn81]

Okay I am totally daft this morning. I need to raise my calcium hardness, typed in my numbers into the calculator like I always do, and it spit out 142 oz by volume. As this is a dry chemical, I just measure it in the same measuring cups, right? I have read not to put too much in at the same time but I don't have a scale to weigh what 142 oz is. Going from 220 back up to 300 on the CH scale.

The pool being 15,000 gallons, can I put all 142 oz in at once or should I split it up to multiple applications? The method I saw here was keep the pump running then spread it around on the surface of the deep end of the pool. Is that it? I haven't done this one yet so it will be my first shot at it.

 

[blazer58]

when adding to my pool, I mixed it in a bucked of water and then poured it into the deep end.
I used a measuring cup also and added less than the pool math stated

 

[ajw22]

It is always good to do multiple doses and sneak up on your objective. That way you don't overshoot CH or CYA which can only be lowered by draining. Add 1/2 to 2/3 of what you think you need, retest, see if you got the expected rise, and calculate next dose.

 

[mknauss]

when adding to my pool, I mixed it in a bucked of water and then poured it into the deep end.
I used a measuring cup also and added less than the pool math stated

It is not advisable to dissolve calcium chloride in a bucket. There is an exothermic reaction and if too much is dissolved in too little of water it can boil and burn you. Just spread in the deep end of the pool and brush it in.

 

[MouseMan54]

Anyone have thoughts on the original question? Do you measure the dry chemical by volume or weight? Does pool math assume a consistent make up of the dry product? In my mind, if there were flakes vs. granules or powder, the volume would be different. For example, if I take a cup of Fruity Pebbles and crush them up into a fine powder, I no longer have a cup (by volume) but I still have the same number of ounces by weight. I'm I, and the OP thinking about this wrong?

 

[mknauss]

Weight is more accurate. But Calcium chloride is not a chemical that needs to be super accurate. Your ranges for the CH in your pool are very wide.

 

[JamesW]

Agree, just estimate the amount.

 

[ChuckTin]

If you are concerned about accuracy you should be careful of the difference between liquid volume measures and dry volume measures.
However I'm doubting that with the quantities and mesurement range (as above) for pool maintenance the difference will be a concern.

 

[ajw22]

You have many estimates in determining the amount of chemicals to be added beginning with your pool volume. So trying to be precise with your measuring while you have all the other variables accomplishes little. That is why I said in post #3 to use multiple doses as you converge on the desired level.

 

[YippeeSkippy]

I have an old diet scale I keep in the pool shed for these times. I do add by weight. The scale has a nice bowl on top of it that I just pour in to and weigh it out then add it to the pool.

Maddie

 

[Skenn81]

So the non accurate method, I have a big old measuring cup (more like a pot) that is 64 oz. I use it when doing my liquid chlorine. So when I do the calcium tomorrow, I will be going off "volume" right? Meaning I will add in 142 oz of powder based on the measuring cup lines? So one full 64, another full 64, and then a bit more. I'll do the thing about adding half, testing, then adding more a few hours later, but I have the basic concept down?

 

[mknauss]

Sounds good. Wait a day or so between additions.

 

[YippeeSkippy]

Don't be surprised it the water looks a little cloudy at first. Its only temporary! Calcium can do that sometimes.

Maddie

 

[riley00dog]

I have been wondering this too as I need to add CH for the first time. I don’t have scales so might just try the measuring cup with the time comes and see what effect it has.

 

[CarolineM]

In pool math it gives you the amount to add by weight or volume. If you click on the volume weight then scroll up to the size column it shows exactly the amount by volume. Example CH add 78 oz by weight or 62 oz by volume. I clicked on the 62 scrolled up and it showed me to add 1 quart, 3 cups, 6 oz.

 

[Skenn81]

Why is there such a debate on the internet on this chemical? Lots of folks say do it in a bucket, others say pour it in, and both sides are very passionate about their methods. I spread it in the deep end and it appears to have dissolved. I moved the area a bit with the brush and couldn't see anything at all left at the bottom. Others out there say it wont dissolve at all and needs to be bucketed before had.

64 oz added today, will add another 64 tomorrow, then test again on Friday.

 

[YippeeSkippy]

As with any chemical we advocate the least amount of fussing with it the better.

In the case of calcium it gets really hot in the bucket. You don't want to splash that on yourself accidentally.

Maddie <--has her safety cap on today

 

[borjis]

I dissolve it in a 2 gallon bucket and pour over a deep end return. Always have and yes the water gets very warm.
Not burn yourself warm though. They key is to not add more than 4 cups at a time to keep it safe from scalding.

 

[JamesW]

As long as you don't exceed about 2 lbs per gallon, the water won't get dangerously hot.

1 lb per gallon is more conservative, but you can go up to 2 lbs per gallon. Mix well by stirring with a plastic stick like a short length of 1/2" pvc pipe.

The calcium chloride should fully dissolve in the bucket with no undissolved calcium chloride.

If you broadcast, just brush well right away.

In some cases, the calcium chloride can stick to the floor of the pool if it sits too long, especially if the water is cold.

You can usually add the full amount in one day as long as you brush the pool well and keep the pump on for at least 12 hours or 24 hours if you add a lot of calcium.

The pool should not cloud up.

Don't add any other chemical that will raise the TA or pH on the same day.

Turn off the salt cell for any large amounts of calcium chloride added.

 

[GeorgiaPoolOwner]

I use the calcium chloride dihydrate for raising CH. They sell it in varying quantities from 5 lbs to 100 lbs. I measure by weight, and I go by the weight on the container. If I need 25 lbs, I use a 25 lb container (or a 20 and 5, or two and a half 10's, etc.).