CYA 500 ppm!!

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D

Desterline

0
Jul 18, 2014
63
Tucson, AZ
So this seems to be a common first post, but I'll do it anyway.
Just bought a new house with my first pool. Yea!! 25,000 gallon, IG, concrete (gunnite and plaster, I believe) with DE Filter in Tucson, AZ. When we got it, there's a floating chlorinator with a handful of 3" pucks in it. Water looks nice enough... I finally got around to having the water tested and they claim the CYA is "over 165" and tell me to drain 60%, refill and retest. Hmmm something fishy here.... Time to get smarter - To the internet!!!

So I've read a ton of this site, ordering my TF-100 test kit, stopped adding "pucks" (been adding liquid chlorine at the moment) and mostly just trying to get my arms around this.
To better understand my CYA level, I diluted a sample (4 parts bottled water, 1 part pool water) and had local the pool store (Leslie's) retest it for CYA. They now claim a CYA level of 99. This fits with what I've learned of the house. It seems the previous owner has been absent for nearly a year and a "friend" has been taking care of the pool - I suspect that "care" has included Dichlor and Trichlor by the truckload... :(

So, it seems a drain and refill is in my future. The kid behind the counter at the pool store seems to think that I should _not_ do that this time of year. Went on and on about how the sun is going to ruin my plaster... Anything to that or just more "high quality" advice from "pool store professionals"?

So, I have other questions...
First, why is it not green? Not that I'm complaining, mind you :) Given a CYA of 500, If I'm understanding the "Chlorine-CYA-Chart" correctly, my minimum FC is 37.5 - no way do I have that much. I've added 3 pucks and 1 gallon of 10% since I closed on the place three weeks ago.

Is the OTO test telling me anything useful at this point? Before adding the liquid, I had barely a tinge of yellow. I interpreted that as effectively zero FC. After a half gallon of 10% and a couple hours of pump time (during the day) it registered about 2. (I added the other half the next day when the test waa showing near zero again.)

-Thanks
Denny
 
Welcome to TFP, neighbor!

The first thing you are going to need to do is invest in one of the recommended test kits and stop having Leslie's test it ... pool stores are notoriously bad at testing, especially the CYA.

You must be lucky to not have a lot of food for the algae, or maybe there is also high copper levels preventing algae from starting?

I agree that now is not a good time to drain the pool. If yoy can not quickly get it filled back up. You could fill and drain at the same time. Fill at the bottom of the deep end and drain at the top of the opposite end. The water will stay fairly separate and should lower the CYA fairly quickly.
 
Wow! !! I took over a sparkling blue pool two years ago that had nothing but stabilized chlorine used in it for years. The previous owner left me several partially used bottles of algaecide.:confused: I kept up his maintenance routine for a long time that eventually ended up with multiple algae blooms until I found the bbb method, bought my own test kit and found my cya was 350. At least you caught it early. Congrats!!
 
I have only heard of two ways to lower CYA. Drain and refill, and reverse osmosis (RO). Being in the southwest where fresh water can be in short supply, I expect you can find a service to do your pool. I think I saw where it costs $500-1000 in CA. I would think you'd be in a similar situation.
 
A bit of googling brought me to these guys http://www.arizonapimachemical.com/services.html I've not spoken with them, but their web site lists a "spring special" for $325 to RO the pool. That seems pretty close to the cost of water for a refill, so... we'll see.

I've now convinced myself that the pool store people are.... well... I'll use the phrase "not useful" :shock:

I'm throwing chlorine in it mostly blind at this point just to buy time till my TF-100 gets here (four days...)

I'm fairly confused at this point. It's not possible that the chlorine is as high as the chlorine/CYA chart would suggest. Probably by a factor of 10 or more. I'll know more when I get decent testing tools.

-Denny
 
Desterline said:
I'm throwing chlorine in it mostly blind at this point just to buy time till my TF-100 gets here (four days...)

I'm fairly confused at this point. It's not possible that the chlorine is as high as the chlorine/CYA chart would suggest. Probably by a factor of 10 or more. I'll know more when I get decent testing tools.

-Denny
Click to expand...
The chlorine/CYA chart lists our recommendations for the minimum FC to maintain for the particular CYA level.
Are you suggesting your chlorine level is higher?
How much chlorine have you added?
 

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Desterline said:
To better understand my CYA level, I diluted a sample (4 parts bottled water, 1 part pool water) and had local the pool store (Leslie's) retest it for CYA. They now claim a CYA level of 99.
Click to expand...
99 seems to be pool store shorthand for "Off the charts." Which would put your CYA at 500. On the other hand, pool stores have reported fresh tap water as having 60 or 90 CYA, too.

What does YOUR test kit say? If you have a TF100, you don't need pool store test results any more. They're usually wrong and they sow the seeds of doubt and confusion. It's like trusting that time & temperature sign at the bank rather than the digital watch on your wrist to tell what time it is.
 
I replaced about half my pool so I'm guessing around 10,000 gallons and my water bill was $145 the next month and the following month which is now its at $62. I'm in Oro Valley, AZ. I don't think your water is much more expensive than mine so I don't think the RO method for $345 is worth it.

I hope you are able to test the CYA value before you replace any water. I've also been bugged by seeing people here in Tucson that have nice looking pools and they are floating pucks. I have a couple guys at work that say they just pay a guy $50 a month and they don't even know what he does but the pool looks nice so they don't complain. So of course when I talk about everything I'm doing it seems obsessive. If pucks would work it would be a cheaper method. It's caused me to have trouble defending using the methods here when I talk to others because they don't have problem pools. I'm spending more time and money than they are. I'm really considering just starting to use trichlor tabs and maintain my FC at 5 or above and just see what happens with the water and do a cost comparison. It really wasn't that much cost to replace water so I can fix things after the experiment.

The methods here are great and you will have a sparkling pool. But I'm afraid you won't get answers to why it wasn't green if you're CYA really is that high...you will mainly just get advice on how to follow the methods here.
 
Your idea of sparkling clear may change once you get the chemistry in balance. A lot of folks have never seen a truly sparkling pool. Once you get used to maintaining your pool, you'll be able to tell something isn't right just by the look and smell of the water. :)
 
Desterline said:
So, it seems a drain and refill is in my future. The kid behind the counter at the pool store seems to think that I should _not_ do that this time of year. Went on and on about how the sun is going to ruin my plaster... Anything to that or just more "high quality" advice from "pool store professionals"?
Click to expand...

Hey I missed this the first time so I wanted to put your mind at ease possibly. I was told the same thing about NOT refilling the pool this time of year and I was all worried about it. I'm in the same area as you and I drained mine several weeks ago and it was already really hot. What I did was rented a sump pump from ACE hardware and I had it all setup and ready to go and I turned it on when the sun got low in the sky and shadows were starting to hit the pool....I think I started at 6pm. The pump was rated for over 5,000 gallons an hour so I was thinking a little over two hours I'd be refilling but it didn't perform up to that rating. It ended up more like 1,700 gallons/hour. It was taking too long so I cut it off at midnight figuring it was close to 50% drained and I had wanted a little more. So I started refilling at midnight with 2 hoses and I stopped the refill at about 11am. I'm estimating it was 9,000 to 10,000 gallons replaced based on using the model I have of my pool in a 3D program. I lowered the water level in the model to estimate how far down I was going to drain. But anyways in the morning when it started heating up to the point where I was worried about the heat on the plaster it was only about 1' to go. What I did was walk out there every so often in the morning and use the fill hoses to spray down the walls.
 
Abigail K said:
The chlorine/CYA chart lists our recommendations for the minimum FC to maintain for the particular CYA level.
Are you suggesting your chlorine level is higher?
How much chlorine have you added?
Click to expand...

No, much lower.
I closed on the house 30 days ago. At that point there was maybe three pucks in a floater. I added about three more pucks the first week and two gallons of 10% bleach since then.
The OTO test (all I have tile the TF-100 arrives next week) has been showing .5 to 4 PPM
 
There are two other ways to do it. One is to let the hose down all the way in the deep end and fill with cold water at the bottom and pump off from the top. The temp difference will help keep the fresh water sitting in the deep end. It isn't perfect but it's one way to do it.
The other is to use a tarp and put the fresh water on top of the tarp on top of the pool and pump from underneath the tarp. If you already have a tarp for winter it's a great way to do it as it's a one for one replacement.

Both ways will keep the water level pretty much normal if you're willing to monitor and adjust the pumping and filling.
 
Gilrock said:
I hope you are able to test the CYA value before you replace any water.
Click to expand...

That's the plan. Just chlorine and acid at the moment until I can get my test kit and make _informed_ decisions. :)

Gilrock said:
The methods here are great and you will have a sparkling pool. But I'm afraid you won't get answers to why it wasn't green if you're CYA really is that high...you will mainly just get advice on how to follow the methods here.
Click to expand...

Hmmm... that's a little sad. I might be mis-quoting it here but I got the impression that the trouble-free-pool method was about _understanding_ the chemistry.
The CYA chart "rules" say FC should be 7.5% of the CYA level. At a 500 CYA that's 37.5 FC. As I understand it that's not even possible to test with the OTO test. I could be unsure of the definition of "sparkling", but I'm sure I'd recognize a green monster :)

(at this point, I'm not even trusting the 500 CYA number, I'm suspecting it to be much higher. I'll know in a few days when I have a real test kit)

To me, one of two things is going on. Either the CYA/Chlorine rule is flawed (unlikely, too many other people use it to good effect for me to completely discount it at this point) OR something else is going on in this pool.
 
So, the chemistry is one aspect. I'm sure with a decent test kit and the information here I can get it under control. The other part.... Where do I stop?

If I'm forced to do a drain and refill... I have a couple different rust stain issues, some dark staining on the floor, some broken/missing diverters, and a non-safety main drain that should be dealt with while it's drained.

I think the filter (DE) is original to the pool, it has several leaks and it's thoroughly caked in crusty mineral stains. At the very least it needs torn down and cleaned - replacement is not entirely out of the question.

I believe the pump is a replacement in the last couple years, but it's a cheap single speed. It seems to have been "hacked" into the system it the cheesiest way possible. I have several pipes abandoned in place running to who knows where. I have a natural gas heater that still has gas (turned off) and electrical connections, but all the plumbing has been sawn off. It's also the mounting point for the really crappy mechanical pool timer.

The KoolDeck is spalling. The concrete deck has no drainage around the sitting wall and lots of cracks - especially around the skimmer.

And I'm considering moving to a SWCG.

I'm having a heck of time trying to justify that kind of expense on a pool that's clean and sparkling today.
 

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