CYA is down to <30! after 1 fall season from 100+!

TFP_Addict

Well-known member
May 19, 2015
85
Burbank, California
I DONT UNDERSTAND!

I was gearing up to empty our pool and do an acid wash because our CYA has always been very very high. And I was dropping crazy amounts of money on chlorine just to keep the pool clear during the summer time.

California has been getting a lot of rain in the last 4 months and the Pool was constantly full of water and likely draining water out to the sewers...

Could the rain water have recycled all the CYA out???

Or is my testing off. I tested it twice!!! I filled the test material on my Taylor test kit all the way to the top and could still see the black dot.

I'm really confused right now and scared, lol.
 

TFP_Addict

Well-known member
May 19, 2015
85
Burbank, California
What CYA did you get the last time you tested it? And when was that?

Is your pool water clear?
The last time I tested it, was probably... 1 year ago? I don't remember. Since it was so High, no one ever uses our pool and I don't use pucks anymore. I figured there was no point to keep testing it.

Our pool is not clear right now. I'm in an epic algae battle for my life.

FC: Zero :( (4 days ago. I dropped 3 gallons of 12.5% and a bag of 70% shock and it's back down to zero)
pH: 8+ :(
ALK: 140-150 (which used to be 110-120 last time i checked)
Cal: 800 :(
CYA: <30

I'm heading to the pool store right now to get more supplies to shock the pool and get it stabilized.

But I was so shocked about my CYA level. Unreal!
 

mknauss

Mod Squad
TFP Expert
May 3, 2014
15,530
Laughlin, NV
It is highly probable that your pool has an ammonia problem.

First - are you going to drain or not? If your CH is 800 ppm, a drain is in order. So determine that first.
Do NOT add any form of CYA. I assume the 'shock' you added was Dichlor. That will just feed the ammonia.

To check and defeat ammonia, if necessary, is to raise your FC in the water using enough liquid chlorine to get to 10 ppm using PoolMath. Circulate the pool for 15 minutes. Test FC. If at 5 or below, add LC to get to 10 using LC, circulate for 15 minutes, repeat until your FC is above 5 ppm after the 15 minute circulation is above 5 ppm.
 

TFP_Addict

Well-known member
May 19, 2015
85
Burbank, California
If my CYA is this low. I'm not going to empty the pool.
The 'shock' I added was Super Shockwave (1 lb)

Ingredients
Calcium Hypochlorite 73%
Other: 27%

I know you're not a big fan of power chlorine. But I remember reading long ago if I was going to use powder to avoid dichlor. Because it also adds CYA.
I also know that hypo Adds alot of calcium to the pool, but I figured at this point, who really cares.. it's already at 800. And hasn't changed much since.
I just bought another 4 gallons of 12.5% bleach.

This whole ammonia issue Seems unlikely to me, But i'm going to take your word for it. So I guess my question now would be.

Wouldn't it better to simply buy a test kit to test for Ammonia? If so, can you recommend one?
 
Last edited:

mknauss

Mod Squad
TFP Expert
May 3, 2014
15,530
Laughlin, NV
Problem with Cal Hypo is your CH is all ready 800 ppm. Which is on the edge of not being manageable to prevent scale.

You can get an ammonia test at an aquarium store. But if you are going to keep the water, and need to SLAM, the liquid chlorine process gets that started regardless.

And if you have algae, and especially if you have ammonia, you will need a whole lot more liquid chlorine than 4 gallons.

If you have 5 ppm ammonia in the water, you will need at least 50 ppm FC added to the water to defeat it.
 
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borjis

LifeTime Supporter
Aug 19, 2014
2,761
Pacific NW
A very important variable in your cya testing....what is the water temp?
Anything below 70 degree water will give you false results. (all the other tests are fine in frigid water)
Best to get it to at least room temp then test.

I learned that the hard way testing cya a year ago.
 

TFP_Addict

Well-known member
May 19, 2015
85
Burbank, California
A very important variable in your cya testing....what is the water temp?
Anything below 70 degree water will give you false results.
Best to get it to at least room temp then test.

I learned that the hard way testing cya a year ago.
After I tested our water 2 times. The water seemed like it was room temp. Not too hot or cold. Then i stored a 200 ML vial to take to our pool supply store for him to check my results.
That 200 ML vial, was in our house for at least 1 hour before I took it. So for sure room temp. He verified the CYA was between 0 and 20 ppm.

Also -- your high pH implies ammonia too. That is one of the indicators.
The pH from our water source is at 7.8 pH. And I rarely ever add acid. I've made posts about it in the past.
 
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