HY-CLOR Calcium Chloride impurities

[samjesse]

I bought HY-CLOR brand Calcium Increaser from bunnings, put 2.5K in a bocket of water, left it 5 days, found that all the white pellets desolved wth dark brown sedements at the bottom of the bocket.
Last time I put some in the skimmer basket in a cloth, I found the same color on part of the filter and now I know why.

Is there a better brand that would not do this?

 

[ajw22]

Let’s see if any of your mates are checking in here this time of year.

 

[aussieta]

i found the same thing and just assumed it was normal

 

[mgtfp]

Never really tried to let a bucket with calcium chloride stand for longer. I always dissolve about 1kg batches in a bucket and pour it into the pool as soon as dissolved. Just used the Hy-Clor Ca increaser last week, no issues. Actually quite like it because it has a reasonably high calcium chloride content. Higher than for example the stuff you get at the Swimart pool stores.

I have read that calcium carbonate with dirt can sometimes look brown. Or maybe iron? Question is whether that came with the product, with the water or with the bucket. Maybe dissolve some in distilled water in a different bucket and try to circle the problem in like that. There certainly are brown calcium carbonate variants. I guess it depends on which other elements are available when calcium carbonate forms.

When you let the bucket stand for long, then you have a very over-saturated calcium solution, sky high CSI in that bucket, so that calcium will deposit. Impurities will probably turn it a certain colour. The impurities might also be already in the pool water (I assume you filled the bucket with pool water?). You should pour the bucket into the pool as soon as the calcium chloride is dissolved, so it gets diluted into the pool and calcium can't fall out of solution (assuming the pool's CSI is in balance).

I am more guessing here. Maybe someone like @JoyfulNoise has a better understanding of the Chemistry that's happening here?

 

[mgtfp]

You got me curious there. Still had half a bag of the hy-clor stuff, just started an experimented. Dissolved 25g each in 100ml of distilled, tap and pool water. Let's see what happens.

 

[mgtfp]

After more than a week, all three samples developed some white sediment as expected, but nothing brown like you had. I assume that there might be something in your water that is creating a coloured type of calcium carbonate. Or the particular batch of hardness increaser you were using had some sort of contamination, but it doesn't seem to be a general problem with this brand.

Have you seen this with other brands?

 

[mgtfp]

Hi @samjesse

I just wanted to add some Hy-Clor calcium chloride to my pool. First used the rest from an old bag (same bag that I used for the test I was describing above), all good, dissolved crystal clear in my bucket. Then I used a new bag, and that stuff instantly created the same brown mess you were describing in your OP. Didn't add it to the pool after all and sent an email to Hy-Clor. Let's see what they come back with. Clearly, something has changed...

 

[Youfah Mizzum]

And I was just about to buy a bag of Bunings Hy-Clor calcium increaser but swung by my local Swimart (my Swimart is closer than Bunnings) & paid around $9 more for the same quantity. Although my wallet is lighter, so is my comfort after reading this!
Let us know what Hy-Clor say.