Maintaining Proper Chemistry

[Phizy]

What has come to my attention just recently is due to the fact that I was not monitoring CYA as often as I should because I was under the ignorant assumption that I was not adding CYA. After looking carefully at the product label, I see now that the New Water cycler pac uses trichlor and therefore has been consistently adding CYA.

I maintain a strict log and therefore have a full history of this past season. Testing was accomplished primarily using the Taylor kit with values checked against the pool store from time to time. In those cases, values were remarkably close that my values from the kit are what I'm reporting.

At the start of the season CYA was at 3 ppm. I charged enough to bring it to 30 ppm. It is now at 60 ppm and I have gone through 6 of the cycler packs since May 4th. The packs contain 6.16 lb of trichlor.

Here in the north east we have not had a substantial amount of rain and therefore I have only bled about 2" of water all season (maybe a little more). For my pool, 1" is roughly 500 gal.

I plan to keep the pool open for another month. Doing some simple math, I come to the conclusion that I will not reach a steady state of CYA this season. Nor will I have draining the pool for closing and much into the next season.

It seems as though I should be maintaining the FC levels using NaOCl (liquid) now and through next season until levels of CYA drop. At that point, I should be able to go back to the automatic chlorinator, but at a low level while monitoring the usage and CYA concentration, toping with NaOCl as necessary.

I would appreciate any corrections or further information to my understanding.

As is typical with most postings, here are my current levels:
FC: 5.8
CC: 0.1
pH: 7.37
TA: 95
CH: 200
CYA: 60
Temp: 85-88°F
Algecide 60 added once a week (small amounts)

Thanks,
Paul

 

[pabeader]

Your reasoning is generally okay. Just a few notes. CYA generally doesn't decrease in any measurable amount. It usually takes months just to drop a few ppm. If you are maintaining the proper FC/CYA ratio, there is no need for algecide. I'm sure there are other things that I'm leaving out, but those jumped out at me, right away.

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Is your pool located inside or outside?

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Looking at the MSDS sheet shows that the pac has both dichlor and triclhor in it.

 

[Phizy]

It is outside

 

[Phizy]

I should add, I know it doesn't degrade, I was referring to the removal through the winterizing and any possible bleed from a rainy season. But, we didn't get a lot of rain this year so I never had to drain off.

 

[pabeader]

Since it's outside, you can save some money by turning off the UV.

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Also, be sure that it's your numbers you use when you post. We really don't trust pool $tore numbers, even if they are similar to yours.

 

[Phizy]

No, I don't need to do that.

They were my numbers. I believe I put that. I also have compared and the store and kit values are very close.

 

[Phizy]

So, here is the thing I don't understand. What is the point of the auto-chlorinator if it inevitably increases CYA? I talked with my father who maintained a pool for years and only checked for chlorine and pH. Constantly used the tabs and never worried about the CYA concentration. It was an AG pool.

 

[pabeader]

The old ways of pool care included dumping and refilling at least once a year. When the pool $tore would say that the water was 'old' or you had something called 'chlorine lock'

Now a days we know the truth and so never need to waste time and money, regularly throwing away water.

They do the same thing to folks with sand filters and 'old' sand. No such thing. All you should ever need is a good, deep cleaning once a year or so.

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Auto chlorine tab devices are good for those times when you are going to be away from your pool, like on vacation. As long as you have planned ahead and have left some room for extra CYA.

 

[Phizy]

Ah. So, then, the more typical addition of chlorine nowadays is manually adding and measuring? I'm good with that.

Maybe that's why every time I've been to the store there was someone with big issues.

 

[Phizy]

So let me ask this then. I grew up thinking all you did was put some tabs in the floater (AG pool growing up), test pH, test chlorine, done. Never had any major issues.

Now, based on this, there is so much more concentration (and knowledge) on maintaining things better. I'm all for that.

So, what do people do now? What does the daily dosing/testing scheme look like. With auto chlorinators (or tabs) you basically set it, check periodically. Do people dose liquid chlorine every day then?

I would imagine a much longer swing of FC rather than a steady value which would change based on use.

 

[pabeader]

In the beginning, when you are first learning your pool, you test FC every day. Input numbers into Pool Math. Dose with chlorine to get back to target. As you learn your pool, you can stretch the time between testing, but you add chlorine every day.
There are a number of good articles and helpers in Pool School.

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Here is an example. Pool School - Basic Pool Care Schedule

 

[Phizy]

Thanks. Is there some paper that shows the biological effects with various FC, CYA ratios?

 

[pooldv]

Some reading in Pool School will be helpful. I think these articles are the best places to start.
ABCs of Pool Water Chemistry
Pool School - Getting Started
Pool School - How to Chlorinate Your Pool

 

[Phizy]

Ok, so now I'm looking for some advice on how really handle next year. Did some reading and not sure of the best way to go.

Option 1. - Continue with the NewWater feeder
Problem with this option is that I will reach 100ppm of CYA based on the current curves within the next year.
This isn't a long term solution
Interesting fact - I asked the pool builder why they suggested this and I have not received a response.

Option 2. - SWG
High initial cost, coupled with other questions I'm uncertain of.
Potential 3yr ROI vs NaOCl liquid?

Option 3a. - Manual dosing of NaOCl
Estimated amount (in gallons) I'll need for the season is 36x where x is the mean loss of chlorine per day. So, 2 ppm loss per day (on average) is 72 gallons
Need to keep on top of this, but will use the NewWater system when on vacation.

Option 3b - Automatic dosing of NaOCl
Not sure of systems/cost/success of this option for residential pools?
Still would need 36x liquid chlorine, but storage is less of an issue

Does anyone have any other thoughts, opinions? I'm basically looking for some guidance on how to handle this next year.

Thanks.

 

[Phizy]

Sorry to bump this, but I was hoping I could get some advice so I can start to plan for next year.

 

[pooldv]

SWG can't be beat for ease of chlorinating your pool. Lots of folks also automate liquid chlorine dosing with a Stenner pump. Posts in the past say that swg vs liquid chlorine has about the same overall cost long term.

 

[Phizy]

For the Stenner pump, what are the parts I would need?

 

[Griswald]

Option 2, SWG.

The swings of FC are eliminated, the excess CYA issue is eliminated and the going away for several days or weeks issue is eliminated.

As to cost, a 3 year ROI would probably align with manual bleach additions according to the math guys on this site.

You just can't beat the convenience...

 

[Salsiccia]

Option 2, SWG.

Plus 1 for SWG from me too.

This is the first pool I have ever maintained, I inherited it when I bought the house a few years ago and after spending the first few years idly doing whatever the LPS told me to do I stumbled across this haven and wealth of knowledge in this forum and have never looked back.

Once I am all balanced, the SWG does does its thing quietly in the background and I just need to keep an eye on CYA and pH and it pretty much looks after itself. I now only test a couple of times a week as that seems sufficient for the usage pattern.

I have also heard people say that a Salt water pool has a "softer feel" to it. I'm not really sure what that means, but I do know that I have never had anything like the "stinging, overchlorinated" experiences that I had in many pools growing up.

If I were building a new pool from scratch I would definitely go salt.

My 2c

Sal

 

[Phizy]

But...if I stick with liquid chlorine, the only draw back is the volume I'll need to purchase. What parts would I get for an auto feeder?