Since taking over the pool after it was built this past spring, the 19,300 gallon pool goes through CYA. I get it up to 50 or even 80 and it is back to <20 within a month. Each time it requires a SLAM which normally takes 3-5 days. What in the world is causing this CYA loss? Plus, now that I am covering it at night with a solar blanket for the past month here in southern FL, I am dealing with cloudy water more so have to SLAM even more frequently. It definitely cleans up to not losing anything over night. Where and why am I losing CYA?
Pool eats CYA
- Thread starter TomHunt
- Start date
Tom,
How much water are you replacing on a weekly basis?
CYA will go down a little each month, but not by 40 or 50 ppm...
It has to go somewhere and a leak is the most likely scenario..
Thanks for posting,
Jim R.
How much water are you replacing on a weekly basis?
CYA will go down a little each month, but not by 40 or 50 ppm...
It has to go somewhere and a leak is the most likely scenario..
Thanks for posting,
Jim R.
1. CYA simply doesn't go away like that. You have an undetected leak or a BIG testing error(s) Both seem unlikely but be assured your CYA cannot disappear like you desribe.
2. Of course, having to SLAM is lack of chlorine, not CYA. You apparently aren't testing your FC to keep it at maintenance levels so algae is the result.
3. I suggest you add enough CYA to get to 50 ppm and then start testing weekly for just a few weeks. Then, test your FC every day or so to make sure you are keeping it high enough to prevent algae.
Post those test results up on the forum and we'll all help.
2. Of course, having to SLAM is lack of chlorine, not CYA. You apparently aren't testing your FC to keep it at maintenance levels so algae is the result.
3. I suggest you add enough CYA to get to 50 ppm and then start testing weekly for just a few weeks. Then, test your FC every day or so to make sure you are keeping it high enough to prevent algae.
Post those test results up on the forum and we'll all help.
I test FC daily. I test CYA weekly; more often when seeing the drops in CYA. I doubt there is any testing error. Normal summer rains for SW FL and then I had overflowing rainfall three weeks ago so the pool needed 40 OZ of CYA from Leslies to get it back to 50 ppm, and have added no more than a inch of water to the pool in the past three months via a hose. The water level of the pool goes down maybe some fraction of an inch weekly probably due to evaporation.
When your water gets cloudy, does it get a "fishy" smell?
Do you get high CC levels?
Do you get high CC levels?
This is perplexing.
The only thing that reliably and predictably lowers CYA is water exchange. However, there is a certain type of bacteria than can convert the CYA to ammonia, but it is unheard of to be repeating over and over, and usually only occurs when FC drops to almost zero.
With that said, the only way that this bacteria could grow is if your FC levels drop below the safe minimum for your CYA level. Same goes for cloudy water/algae.
How & where do you perform the CYA test? What is your daily FC target (in % of CYA)?
As requested, post up a complete set of test results so we know what we are working with.
Then you have chosen an FC target too low. That you need to SLAM at all demonstrates that.
It seems you have two parameters that are causing trouble.....FC and CYA. I would focus primarily on keeping the FC at acceptable levels and then weekly tests of your CYA making certain it stays right around 50
borjis
LifeTime Supporter
Ya what test kit are you using?
Are you testing the CYA with your back to the sun, holding the vial waist high and looking
for the black dot then looking away then back to the dot again as you fill it?
It's the most difficult test to do and when I started first doing it I was doing
it all wrong getting incorrect readings.
My CYA goes to near zero every spring, but nothing like the loss
you are having.
Are you testing the CYA with your back to the sun, holding the vial waist high and looking
for the black dot then looking away then back to the dot again as you fill it?
It's the most difficult test to do and when I started first doing it I was doing
it all wrong getting incorrect readings.
My CYA goes to near zero every spring, but nothing like the loss
you are having.
Attached is my log of pool activities since opening the pool. This summer we had enough rain (which did overflow some to grade) that I didn't add any city water until this fall. I have added maybe 1" since the rains stopped weeks ago as the level was getting near the bottom of the skimmer return. I have the 50ppm test standard CYA comparison sample (which at 50 ppm, is not completely hiding the black dot BTW) so have a good idea of what to expect when testing. My FC never gets to 0. I am suspicious that the solar cover is responsible for the cloudy water this time as it is very cloudy and became cloudy faster than normal. I run my variable speed pool pump 24/7 at 1800 rpm (not very expensive at that speed and it keeps the SWG running overnight.
I couldn't get my spreadsheet to attach so I took screenshots of the last few months history.
I couldn't get my spreadsheet to attach so I took screenshots of the last few months history.
Sorry I missed your question; no fishy smell. AND, the pool is in a cage so it is unlikely that the fertilizer guy spread any fertilizer into the 20 / 20 screen on his Oct visit. I watched him spread 140 # of 25 / 0 / 11 in granules and didn't notice any overspread.
The fertilizer may not have been placed directly into the pool, but you mentioned overflowing rains...is it possible any fertilized areas were also flooded and you got fertilized runoff into the pool?
No, not possible. The cage is 10" over grade in a cage. Overflowing volumes run out via a drain (drain can't back flow) long before the water level in the pool reaches the top of the deck.
- May 3, 2014
- 58,351
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
What brand of CYA are you using? We have had anecdotal reports that the Clorox brand seems to not always add the CYA to the water that it should based on PoolMath.
CYA does not disappear chemically under normal circumstances. It will degrade slowly. So it must be either the product is not consistently effective or a significant amount of water is being replaced or there is random testing error.
Take care.
CYA does not disappear chemically under normal circumstances. It will degrade slowly. So it must be either the product is not consistently effective or a significant amount of water is being replaced or there is random testing error.
Take care.
- May 23, 2015
- 24,403
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
I think you have your answer - rain water dilution. You have an overflow built into your pool so, when it rains, the water rises to the overflow and then leaves the pool. You said you added no water all summer long, so I’m guessing you’ve gotten some pretty decent rainfall.
Not sure if you answers this but does your pool have an auto fill?
Not sure if you answers this but does your pool have an auto fill?
The main suspects are dilution, testing error or bacteria.
The cloudiness makes me think that bacteria might be involved even though it's probably the least likely cause overall.
If the chemistry and filtration are good, then the pool should not get cloudy.
Does the loss of CYA coincide with the water getting cloudy?
The cloudiness makes me think that bacteria might be involved even though it's probably the least likely cause overall.
If the chemistry and filtration are good, then the pool should not get cloudy.
Does the loss of CYA coincide with the water getting cloudy?
Leslie conditioner granules. It does raise the CYA. I have added around 60 oz since Friday and am back to 40- 50 ppm. I do not have auto fill and we have had only two rains that were heavy enough (besides Irma) to cause any overflow draining and then not that much. As to chemistry, you can see by my pool history spreadsheet that I don't let the FC get low. If anything, I keep it too high. Testing error is always possible, but not likely. With the std test sample included in the TF100 kit, and with my wife also watching, we are pretty good at it by now (we have had several refills from the TF folks).
If you're getting cloudy water, something is off. Typically algae, bacteria, a filter problem or high CSI.
What filter do you have?
What filter do you have?