Very high CYA level questions

#1
I'm new to the forum, and new to test kits.
I've been using trichlor tablets because... well that's what the store was selling me, and they seemed to fit nicely in my chlorinator. But i couldn't ever get my chlorine levels to settle down, so i came here and bought a test kit.
Lo and behold, i find my CYA to be crazy high.

FC = 5.5
CC = 0.5
TA = 100
CH = 390
CYA = 120

(fyi, i got a CYA value over 100 by using jblizzle's suggested method of testing 50/50 pool/tap water and doubling the result.)

Here's my question:

Pool calculator says to bring down CYA i need to replace 67% of my water.
That's an awful lot!
We don't even empty the pool that much when we close it for the season.
(The contractor said something about how the concrete structure will "float" out of the ground without the weight of that water)

So provided i'm an a-hole who is [s:2xjivxte]unwilling[/s:2xjivxte] reluctant to empty the pool in the middle of the swim season, what do these high CYA levels mean for me?
Short term?
Long term?
Any tips or advice for dealing with high CYA?
Or, would you rather berate me for running this high CYA? i guess i'll take that too. Maybe you'll shame me into emptying my pool.

If i keep using the trichlor i'm assuming the CYA will continue to rise. Does that even matter at this point?
That's actually a serious question. Any reason not to keep dumping CYA into the pool via trichlor pucks now that i'm already at such a high level?

Any help or advice is appreciated.
This stuff is all totally foreign to me.
Thanks!
 

pwrstrk

TFP Expert
LifeTime Supporter
Aug 17, 2012
4,758
Elverson Pa.
#2
Welcome to TFP.

You can do partial drain, refills. Just say one third at a time or so.

If it were me I'd want to lower the CYA level. That high of CYA is hard to keep the proper FC levels which lead to algae outbreaks. The trichlor is going to make things worse. That's why we don't recommend using it on a regular basis. Also they are acidic and lower PH.

Make sure you do some reading in pool school. Good job on getting a test kit.


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Isaac-1

TFP Expert
LifeTime Supporter
May 10, 2010
6,711
SW Louisiana
#3
We understand that this can be hard news to accept, most of the time we don't get to hear from people here until after the pool has turned green with algae, a condition that is almost impossible to cure with high CYA levels. If your water is still clear and you are passing an over night chlorine loss test, you may be able to get away with these high CYA levels for a time until you can gradually reduce them. This is not the best option as continued high CYA levels increase your chance of algae outbreaks, continuing to use trichlor will just make it worse. It is not a gamble I would willingly take though, and would only avoid water replacement if your in an area with seasonal water rationing.

Ike

p.s. at your current CYA level you should always maintain an FC level of at least 9, and a target level of around 13, anything below this risks algae taking over see the extended CYA / Chlorine chart at chlorine-cya-chart-t2346.html the one in pool school only goes up to a CYA level of 100
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
41,197
Tucson, AZ
#4
And to add to the PS in Isaac's post ... a bonus of maintaining the FC that high is that the pH test is not accurate when the FC > 10ppm.

I would suggest:
Do an OCLT test with the FC up around 20ppm ( you need a FAS-DPD test for that).
If you pass and the water is clear, you could try to keep it that way using bleach ... NO MORE TRICHLOR or the CYA is going to keep climbing.
If you fail or the water is green, either order bleach by the tanker or replace water because you need to SLAM the pool.
 

Donldson

TFP Expert
LifeTime Supporter
In The Industry
Jun 12, 2009
3,266
NW Ohio
#5
Failed_Chemistry said:
If i keep using the trichlor i'm assuming the CYA will continue to rise. Does that even matter at this point?
That's actually a serious question. Any reason not to keep dumping CYA into the pool via trichlor pucks now that i'm already at such a high level?
Well, if you keep using it you will have to use more to keep the FC in check. That will increase your CYA even faster. At 200 if you want to get it fixed you will need to drain 75% of your water. At 300 you will have to replace 85% of your water. Shall I continue?

I won't give you heck, but life would be far easier if you just fixed it now and be done with it. Just something to chew on.
 

Jeetyet

Well-known member
Jul 29, 2012
200
Florida Panhandle
#6
If you're REALLY against draining a lot of water at once you could just stop using the pucks and switch to liquid chlorine now in order to stabilize your CYA at your current level, then replace water a little at a time as it rains. This should lower your CYA substantially before its time to winterize (dependent upon rainfall amounts of course). Whatever percentage you drain to winterize would then get you closer to target level, if the rain draining hasn't already gotten you there. Of course you could accelerate the process at any time by small drain/replace increments along the way as often as you're inclined to.

Something you might wish to consider, though I doubt anyone here would condone it, myself included, is to target a CYA at the very low end of the suggested range for closing/next year's opening. Then, once you open you could use the pucks until your CYA climbed to the upper end of the range, then switch over to liquid again. And of course the time interval before hitting the upper limit could be extended by more frequent smaller drain/refills. This might be an option for you if you're frequently away for several days or for whatever reason you can't or don't want to devote the attention to your pool being a BBB purist requires. :-D
 

Donldson

TFP Expert
LifeTime Supporter
In The Industry
Jun 12, 2009
3,266
NW Ohio
#7
Jeetyet said:
devote the attention to your pool being a BBB purist requires. :-D
I hardly call 3 minutes a day devotion. That's less time than I spend brushing my teeth. I guess if I refused to "devote" those few minutes brushing my teeth a day I could. Of course then instead of nice cavity free checkups I would spend hours at the dentist drilling and in pain and thousands of dollars. So does it make sense that I should keep spending those few minutes a day on upkeep instead :?:
(Credit to Richard for the analogy)
 

Jeetyet

Well-known member
Jul 29, 2012
200
Florida Panhandle
#8
Donldson said:
Jeetyet said:
devote the attention to your pool being a BBB purist requires. :-D
I hardly call 3 minutes a day devotion. That's less time than I spend brushing my teeth. I guess if I refused to "devote" those few minutes brushing my teeth a day I could. Of course then instead of nice cavity free checkups I would spend hours at the dentist drilling and in pain and thousands of dollars. So does it make sense that I should keep spending those few minutes a day on upkeep instead :?:
(Credit to Richard for the analogy)
I apologize that my choice of words offended you. That certainly was not my intention. I'll keep my big mouth shut from now on.
 

techguy

TFP Expert
LifeTime Supporter
Jul 21, 2010
2,697
Antelope, CA
#9
No, you are right, it does require dedication to make work, it's just about as much dedication it takes to feed a pet. We need to do these things daily or you end up with an angry green pool instead of a angry, hungry pet.

Stick around, we like people and we were all new once. You should have seen my pool before last year...duck pond?
 

CUTiger78

Well-known member
May 24, 2009
463
NoVA
#10
Jeetyet said:
I apologize that my choice of words offended you. That certainly was not my intention. I'll keep my big mouth shut from now on.
Oh, don't apologize - we could use a little levity. :party:

BTW, yes, I did. I ate lunch. Chinese food.
 

Donldson

TFP Expert
LifeTime Supporter
In The Industry
Jun 12, 2009
3,266
NW Ohio
#11
Jeetyet said:
I apologize that my choice of words offended you. That certainly was not my intention. I'll keep my big mouth shut from now on.
Wasn't offended, and I cannot comment on the size of your mouth (since I don't know you) but you certainly don't have to keep it shut. I just wanted to correct the perception that the life revolves around your pool. Typically it is the exact opposite, you get your life back from the pool and pool store.
 
Apr 18, 2013
17
St. Louis
#12
I was in a very similar situation and am located close to St. Louis. I had a very high CYA level (I think around 250 or something) when I opened up the pool this spring. First time pool owner with the purchase of a new home. The pool had been "professionaly" maintained which I am assuming that someone came once a week and made sure the chlorine and PH levels were appropriate and adjusted accordingly and just ran the chlorine feeder at max and never checked TA, CH, or CYA.

I did not know much about the pool but knew that it had a fiberglass shell and was afraid of draining the pool and popping the pool out of the ground. After getting in the pool I discovered that is is a concrete floor and fiberglass side. What I ended up doing was siphoning water down the hill (continously) and filling it back up with a hose when it dropped about 2 feet. I did this for about 2 weeks. Eventually I got my CYA down to 70 and considered that good enough. I ended up spending about $300 or $400 in water but was probably only $100 or $200 more than if I had just drained and filled up and I figured a pool crack or something would be much more expensive than a couple hundred bucks.

I still use my chlorine trichlor feeder but pretty much just use it on a low setting and use it to top off my chlorine levels and regulate my CYA without having to add stabalizer. My CYA is around 50 now. Most of my chlorine is coming from bleach. I am no expert, but I haven't seen any negative affects of running the chlorine feeder at low levels as long as all of the chemical levels are appropriate and getting most of my chlorine from bleach.

Something that took me a second read through pool school was to understand the importance of how the CYA and chlorine levels are dependent of each other and either one too low or too high has negative affects. It definitely is not one of those "well if a little is good then a lot is better" things.

This is the basis I got
Too low of chlorine - Algae/Bacteria growth
Too high of chlorine - Stinging eyes
Too low of CYA - Chlorine gets burned off by sunlight before it gets a chance to attack Aglae/Bacteria
Too high of CYA - Chlorine becomes less effective thus needing super high levels of chlorine just to stay effective.
 

pwrstrk

TFP Expert
LifeTime Supporter
Aug 17, 2012
4,758
Elverson Pa.
#13
tooclosetosee said:
I was in a very similar situation and am located close to St. Louis. I had a very high CYA level (I think around 250 or something) when I opened up the pool this spring. First time pool owner with the purchase of a new home. The pool had been "professionaly" maintained which I am assuming that someone came once a week and made sure the chlorine and PH levels were appropriate and adjusted accordingly and just ran the chlorine feeder at max and never checked TA, CH, or CYA.

I did not know much about the pool but knew that it had a fiberglass shell and was afraid of draining the pool and popping the pool out of the ground. After getting in the pool I discovered that is is a concrete floor and fiberglass side. What I ended up doing was siphoning water down the hill (continously) and filling it back up with a hose when it dropped about 2 feet. I did this for about 2 weeks. Eventually I got my CYA down to 70 and considered that good enough. I ended up spending about $300 or $400 in water but was probably only $100 or $200 more than if I had just drained and filled up and I figured a pool crack or something would be much more expensive than a couple hundred bucks.

I still use my chlorine trichlor feeder but pretty much just use it on a low setting and use it to top off my chlorine levels and regulate my CYA without having to add stabalizer. My CYA is around 50 now. Most of my chlorine is coming from bleach. I am no expert, but I haven't seen any negative affects of running the chlorine feeder at low levels as long as all of the chemical levels are appropriate and getting most of my chlorine from bleach.

Something that took me a second read through pool school was to understand the importance of how the CYA and chlorine levels are dependent of each other and either one too low or too high has negative affects. It definitely is not one of those "well if a little is good then a lot is better" things.

This is the basis I got
Too low of chlorine - Algae/Bacteria growth
Too high of chlorine - Stinging eyes
Too low of CYA - Chlorine gets burned off by sunlight before it gets a chance to attack Aglae/Bacteria
Too high of CYA - Chlorine becomes less effective thus needing super high levels of chlorine just to stay effective.
Right on point except PH out of range burns eyes.


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jackrogue

LifeTime Supporter
Dec 8, 2012
30
Kailua-Kona, HI
#15
The pool had been "professionally" maintained which I am assuming that someone came once a week and made sure the chlorine and PH levels were appropriate and adjusted accordingly and just ran the chlorine feeder at max and never checked TA, CH, or CYA.
Yessirreee ---- that was my experience with my previous "PROFESSIONAL" service. He maintained the trichlor puck in each strainer and brushed the pool walls and floor weekly ---- and NOTHING else.