Cyanuric Acid Solubility

[TomU]

Do any of you chemistry experts know if the solubility of cyanuric acid increases with temperature? I've looked at multiple MSDS documents from different manufacturers to no avail. I'm curious if taking granular cyanuric acid and letting it boil for awhile in a pot of water would dissolve it faster for subsequent addition to the pool. Based on the information in the MSDS, boiling wouldn’t come anywhere near the melting point of the acid, and from what I can tell, there wouldn’t be any fire danger with it already submerged in water.

Tom

 

[chem geek]

Most chemicals that dissolve in water are more soluble at higher temperatures (calcium carbonate is a notable exception) and I believe CYA is more soluble at higher temperatures. So you should be able to dissolve it more quickly in hot water. Another option is to use the monosodium salt of CYA in a slurry since it is already dissolved and will mix with pool water instantly. It is made by Natural Chemistry and is called Instant Pool Water Conditioner and may be found here.

Richard

 

[TomU]

Thanks Richard. I guess as a follow up, from what I can tell, cyanuric acid placed in 80 or 90 water dissolves ridiculously slowly. Do you think another 100 degrees will make a noticeable difference? Let say it takes 7 days to dissolve 1 lb. I'm not going to try this if it will still take 3 days at 212 degrees F. If you think it might happen in a hour or so, I might give it a whirl.

 

[chem geek]

I really don't know. If you find out, let us know. It's a rather stable molecule so the near boiling water shouldn't harm it.

 

[TomU]

Well, I tried it (sort of). I decided that being an acid, I wasn't real excited about placing it in my wife's nice teflon coated aluminum pans. Instead what I did was boil water and then pour it over the acid in a glass bowl. I stirred it every minute or so for about 15 minutes and saw virtually no change. Immediately after stirring, the granules would return to the bottom of the bowl. At this point I decided it wasn't worth my time and just added it to the skimmer (two days ago). It must still not be dissolved because I've haven't seen the rise in the CYA test I'm expecting yet.

 

[LadywithIron]

I was sure in hopes that this would work, I have an intex pump and paper filter, and I just cannot go a week without washing that filter out. I have the CYA hanging in a nylon near the outflow, but it's a slow process because some of the little particles still escape and get into the filter, and get washed away.

I thought of maybe putting the CYA into a seperate container to dissolve for a week, but without circulation of any kind I wonder if that would work.
As soon as I remember to get an extra bucket, I am going to try this.

 

[rpgman]

what type of intex pool...??

I have a metal frame one, 18x42 or 48 I can't remember, oval shaped, and I added CYA right into the skimmer, but I have upgraded the filter to a Hayward sand filter, I think it's and 18 and the pump is a 1/2hp flow pump.....works great with my size pool....the inflow jet reaches the middle of the pool, so I;m guessing it'll circulate the entire pool in less then an hour and a half to 2 hours....

those filters that come with the intex pools aren't very efficient imo.

 

[Wolfmarsh]

I put 3 pounds of CYA in a sock and stuck it in my skimmer and the sock was empty in 24 hours.

I was wondering if the particles went through the sock, but I checked my CYA level and it was where i had expected it to rise to.

Maybe some brands dissolve faster than others? (due to smaller particle size or something)

 

[JohnT]

I put 3 pounds of CYA in a sock and stuck it in my skimmer and the sock was empty in 24 hours.

I was wondering if the particles went through the sock, but I checked my CYA level and it was where i had expected it to rise to.

Maybe some brands dissolve faster than others? (due to smaller particle size or something)

There was a discussion on PF a year or so ago, and there were a few of us that had no trouble getting CYA to dissolve overnight. I expect it has to do with some aspect of water chemistry, but I don't know what it would be. At the time, my alkalinity was high and my calcium hardness low.

 

[rpgman]

I just did that last Friday, dissolved 1.75 pounds of Stabilizer by putting it in the skimmer....for a 6250 gallon AG pool.

my alkalinity was 150 and my calcium hardness was 40.

I had 0 CYA when I started and overnight the next day I was at 35.

 

[LadywithIron]

Well it wasn't such a challange to raise the CYA after all, I stuck the nylon with the CYA into the water, near the ouflow, and 2 days later, I have a 35 reading for CYA, and almost all of the CYA was still in the nylon! So I just removed that thing ASAP.

I used the pool calculator to measure, and am certain that I got this right, I am thinking there is something screwy with the CYA, hth brand, Walmart.....

I am just glad that I checked it when I did. Two different test a day apart are showing the same CYA.