Cyanuric Acid

[aylad]

Aylad I have already drained 1/2 of the pool about 1 week ago!

I know that you drained a good bit--but the CYA numbers that you've posted are still very high. So you'll either need to drain/refill some more in order to lower it, OR keep your chlorine levels high (8-15) in order to compensate for it. Which decision to make is yours--I don't know how feasible they are to you.

Can you make a guess as to when my chlorine will drop to around 10?

I would say by late today or tomorrow. It doesn't take long after a rainstorm!

Janet

[Sue225]

If you have cc does that mean something is trying to bloom? My FC is now down to 11 and cc is .5 We had bad storms yesterday and I have not had a chance to vacuum bottom of pool. Do you think that is why my cc went up to .5 from 0?
Thanks for all your help. I have learned so much about pool chemistry!!!

[Watermom]

The rain probably dropped some debris in the pool which can cause a little CC. As long as you are no higher than 0.5 you are ok. Or, you can go ahead and shock the pool and that will take care of it.

[Sue225]

CC was o this AM!!! My test vial was dirty. Washed and dried it and cc was perfect!

Question is my fc is now 8 i do not want it to go lower. How much chlorine should i add tonight to get it up to 11 since i am losing about 3 ppm each day with this heat and sun.
thanks in advance

[Watermom]

In your pool, each quart of 6% bleach should add approximately 1ppm of chlorine. So that makes it easy to know how much to add --- 3 quarts.

[StevenB92]

I slightly remember years ago I read somewhere that if the pool is calm for a while that the CYA will "float" to the top and then you can remove that water, e.g. via the skimmer, thus removing a higher concentration of CYA. Also I believe that the article/post/whatever it was suggested siphoning off the top while having a water hose in the bottom of the pool slowly adding water and "pushing" the higher concentration CYA water towards the siphon.

About a year ago a co-worker told me a pool store guy verified the idea that the CYA will stratify in a calm pool and that to remove the most CYA let the pool settle and then remove the water from the top.

I have been meaning to test my water with the pump running for the "normal" cya level and then after letting the pool sit overnight test the water from a couple inches and then a couple of feet down to see if there is any difference.

Anybody else hear anything similar to this?

[aylad]

First time I"ve heard of it....but my pool is very rarely calm so it wouldn't matter!

Janet

[waterbear]

I slightly remember years ago I read somewhere that if the pool is calm for a while that the CYA will "float" to the top and then you can remove that water, e.g. via the skimmer, thus removing a higher concentration of CYA. Also I believe that the article/post/whatever it was suggested siphoning off the top while having a water hose in the bottom of the pool slowly adding water and "pushing" the higher concentration CYA water towards the siphon.

About a year ago a co-worker told me a pool store guy verified the idea that the CYA will stratify in a calm pool and that to remove the most CYA let the pool settle and then remove the water from the top.

I have been meaning to test my water with the pump running for the "normal" cya level and then after letting the pool sit overnight test the water from a couple inches and then a couple of feet down to see if there is any difference.

Anybody else hear anything similar to this?

I have heard that and I have also heard the opposite, that it sinks to the bottom and it is removed by shutting off the skimmers and opening the main drain. I have heard these conflicting stories at product trainings put on by manufacturers that I attended.

BTW! I can tell stories about some of the slight of hand "demos" that I've seen at these too, like the one that 'proved' that MPS makes chlorine 'reappear in the water --glass of tap water which will have chlorine, add OTO so it turns yellow, stick in finger which uses up the chlorine so water turns colorless, add a pinch of MPS (non chlorine shock) and yellow returns but NOT because the chlorine reappeared ad the trainer (who was president of this particular product company!) said but because OTO will turn yellow in the presence of any oxidizer and is not specific for chlorine!)

Is it any wonder that many pool stores give out so much misinformation? Most of what they learn about water chemistry comes from 'trainings' like this!

Getting back to CYA, both are false. Once CYA dissolves it exists as an ionic species in the water and will be evenly distributed as cyanuate ion through out the water. It's basic chemistry!